List of Issues

Chinese Journal of Catalysis
2023, Vol. 47
Online: 18 April 2023

Previous Issue    Next Issue

Cover: Associate Professor Yanmei Shi and Professor Bin Zhang et al. reported that partial dopants of S-doped carbon materials were dissolved in the form of SO₄^2– during the alkaline OER process, and the newly generated benzoquinone group was identified as a real OER active species by multiple characterizations.

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Review

Select

Heteronuclear dual-metal atom catalysts for nanocatalytic tumor therapy Jingyi Han, Jingqi Guan 2023, 47:  1-31.  DOI: 10.1016/S1872-2067(22)64207-4 Abstract ( 330 )   HTML ( 27 )   PDF (17654KB) ( 452 )   Due to excellent catalytic activity and high atomic utilization rate, single atom catalysts (SACs) have become a rising star in the field of nanocatalytic medicine. Heteronuclear dual-atom catalysts (HDACs) retain the advantages of monoatomic catalysts, have more optionally regulated coordination environment, possess favorable synergistic effects between different active sites, and can break through the restriction of adsorption ratio of SACs, making them the most ideal candidates for catalytic tumor therapy. In this review, we first introduce the advanced characterization methods of HDACs. Then, HDACs in different application fields are classified and elaborated according to various preparation strategies. According to the pharmacodynamic mechanisms, the application of HDACs in the field of nanocatalytic tumor therapy is emphatically introduced. Finally, a concise but focused summary and perspective is provided to outline the current challenges and prospects for future development of HDACs for oncology therapy.

Select

Syntheses and applications of single-atom catalysts for electrochemical energy conversion reactions Qi-Ni Zhan, Ting-Yu Shuai, Hui-Min Xu, Chen-Jin Huang, Zhi-Jie Zhang, Gao-Ren Li 2023, 47:  32-66.  DOI: 10.1016/S1872-2067(23)64392-X Abstract ( 543 )   HTML ( 36 )   PDF (14367KB) ( 544 )   Singe-atom catalysts (SACs), as heterogeneous catalysts, have attracted increasing attention in recent years owing to their numerous advantages in the field of electrocatalysis, such as a high atom-utilization rate and unique structural characteristics. In this review, we introduce various preparation methods for obtaining SACs based on top-down and bottom-up synthesis strategies and the corresponding research progress made in recent years. We also focus on the electrocatalytic applications of SACs containing noble metals (Pt, Pd, Ir, etc.) and non-noble metals (Fe, Cu, Co, etc.) in the oxygen evolution reaction, hydrogen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, and nitrogen reduction reaction. Finally, the future challenges and prospects of monatomic catalysts are also discussed.

Select

Reaction mechanism of methanol-to-hydrocarbons conversion: Fundamental and application Runze Liu, Xue Shao, Chang Wang, Weili Dai, Naijia Guan 2023, 47:  67-92.  DOI: 10.1016/S1872-2067(22)64209-8 Abstract ( 670 )   HTML ( 34 )   PDF (25108KB) ( 977 )   As a significant reaction in heterogeneous catalysis, methanol-to-hydrocarbon (MTH) conversion supplies a sustainable way for the production of important platform chemicals, e.g., olefins, gasoline and aromatics. Although many commercial MTO plants have already been operated in China recently, the catalytic efficiency, i.e., the olefins selectivity and the catalyst lifetime still need to be improved. Consequently, extensive attentions have been attracted to the fundamental insights into the reaction mechanism to provide the guidance for catalyst design and optimization. In this review, recent progress in the reaction mechanism of MTH reaction, including the formation and evolution of the first C-C bond species, is emphasized. Based on the reaction mechanism, the catalyst design and optimization for enhancing the target product selectivity and promoting the catalyst lifetime, which are still missed in recent reviews, are also highlighted. The present review will provide a theoretical reference for understanding the reaction mechanism of MTO reaction and shed a light on the development of highly efficient MTO catalysts.

Select

Advanced in-situ electrochemical scanning probe microscopies in electrocatalysis Dan-Qing Liu, Bingxing Zhang, Guoqiang Zhao, Jian Chen, Hongge Pan, Wenping Sun 2023, 47:  93-120.  DOI: 10.1016/S1872-2067(23)64396-7 Abstract ( 1187 )   HTML ( 81 )   PDF (6576KB) ( 1109 )   Electrocatalysis is critical in improving the energy conversion efficiency, decreasing carbon emissions, and promoting the development of the green energy industry. A deep understanding of the electrocatalytic processes at nanostructured electrochemical interfaces (electrodes) is required to elucidate the electrocatalytic mechanism and facilitate the rational design of electrocatalysts. Electrocatalytic surfaces, which are structurally and compositionally heterogeneous, are usually analyzed using classical macroscopic electrochemical methods that lack the high spatial resolution and temporal sensitivity required for localized electrochemical measurements. In this regard, advances in electrochemical scanning probe microscopy, including electrochemical scanning tunneling, electrochemical atomic force, scanning electrochemical, and scanning electrochemical cell microscopies, offer significant opportunities to study electrocatalytic phenomena at nanometer and ultimately atomic scales during the reaction process. In this review, we first introduce the basic principles, features, and advantages and disadvantages of each technique of these scanning probe microscopies and outline the key advancements of each technique, particularly in investigating electrocatalysis. Subsequently, hybrid techniques of probe microscopy with synergistic effects are introduced. Then, we summarize the recent progress in the application of in-situ characterization methods in electrocatalysis, including hydrogen evolution/oxidation, oxygen evolution, and CO2 reduction reactions, focusing on the structure-activity correlation, structure evolution/stability, adsorption of the reactants or intermediates, preferred reaction pathways, and selectivity. Finally, the challenges and future developments of in-situ scanning probe microscopy in electrocatalysis are discussed.

Communication

Select

SET or TET? Iron-catalyzed aminocarbonylation of unactivated alkyl halides with amines, amides, and indoles via a substrate dependent mechanism Han-Jun Ai, Fengqian Zhao, Xiao-Feng Wu 2023, 47:  121-128.  DOI: 10.1016/S1872-2067(22)64208-6 Abstract ( 232 )   HTML ( 5 )   PDF (1086KB) ( 579 )   Supporting Information Iron-catalyzed carbonylation reactions are highly desirable in our sustainability-advocating chemical community because of its low cost, abundance, and potential for distinct and complementary reactivity patterns. Meanwhile, alkyl bromides as well as low nucleophilic amides and indoles are considered to be particularly challenge substrates for carbonylation reactions. Herein, we report an iron-catalyzed carbonylative coupling of unactivated alkyl halides with amines, amides, and indoles to assemble amide structural units, affording various amides, imides and N-acyl indoles with excellent yields and unprecedented functional group compatibility. Remarkably, our approach also represents the example on Fe-catalyzed aminocarbonylation of alkyl halides. Our preliminary mechanistic studies suggest that the reaction pathway is substrate dependent: the carbonylation proceeds via a radical pathway when alkyl iodides were used; while a two-electron transfer (TET) process occurred when alkyl bromides served as the electrophiles.

Article

Select

Unveiling inactive sulfur residue and benzoquinone moiety formation in sulfur-doped carbon for water electrooxidation Zhipu Zhang, Shanshan Lu, Bin Zhang, Yanmei Shi 2023, 47:  129-137.  DOI: 10.1016/S1872-2067(23)64394-3 Abstract ( 229 )   HTML ( 7 )   PDF (930KB) ( 411 )   Supporting Information Doping carbon materials with heteroatoms is an effective strategy to improve the catalytic performance of carbon materials through charge redistribution. Furthermore, heteroatom-doped carbon materials have been proven to be unstable and can be completely removed from the electrode via the electrochemical oxygen evolution reaction (OER). However, since S has a electronegativity similar to that of C, the behavior of S-doped carbon materials under OER conditions might differ and thus deserves special attention. In this study, we investigated the structural evolution of S-doped carbon materials during the alkaline OER. It was observed that the S-doped graphite flake (S-GP) underwent oxidization. Notably, only partial S dopants dissolved in the form of sulfates, resulting in the emergence of new forms of S- and O-containing groups on the electrode. The results from well-designed experiments demonstrated that despite remaining on the electrode, the S-containing groups had no effect on the OER activity, and the high OER activity was attributed to the derived benzoquinone moiety. The dissolved sulfates further promoted OER activity when S-doped carbon materials were used as substrates for the Ni(OH)2 anode. Our work reveals the real activity origin of S-doped materials towards OER, motivating researchers to reconsider the catalytic mechanism of the S-doped carbon materials and their supported composites for other reactions.

Select

An efficient way to use CO2 as chemical feedstock by coupling with alkanes Changcheng Wei, Wenna Zhang, Kuo Yang, Xiu Bai, Shutao Xu, Jinzhe Li, Zhongmin Liu 2023, 47:  138-149.  DOI: 10.1016/S1872-2067(23)64416-X Abstract ( 359 )   HTML ( 20 )   PDF (4526KB) ( 568 )   Supporting Information The most promising method to eliminate CO2 is to find large-scale and value-added applications of CO2 as a carbon resource. However, the utilization of CO2 as feedstock for basic chemicals has long been a great challenge owing to its high thermodynamic stability. Herein, we report the coupling conversion of CO2 with light alkanes over the HZSM-5 zeolite with much higher aromatic selectivity than light alkanes as the only reactant. A CO2 conversion of 17.5% and n-butane conversion of 100% with aromatic selectivity of 80% could be achieved by the coupling reaction at the CO2 to n-butane ratio of 0.475, in which CO2 not only acted as an agent for balancing hydrogen in the reaction but also partly (~25%) incorporated into the aromatic products. Methyl-substituted lactones (MLTOs) and methyl-substituted cycloalkenones (MCEOs) were identified as key intermediates during the coupling reaction. 13C isotope labeling experiments, 13C solid-state NMR, in-situ diffuse reflectance infrared Fourier transform spectroscopy, and density functional theory (DFT)calculations revealed that CO2 could react with carbonium ions generated from alkane cracking to form MLTOs, which could further get converted into MCEOs, thus generating aromatic compounds. This coupling reaction provides guidance for the direct utilization of CO2 to produce value-added chemicals with the simultaneous transformation of light alkanes.

Select

2D carbon nitrides: Regulating non-metal boron-doped C3N5 for elucidating the mechanism of wide pH range photocatalytic hydrogen evolution reaction Sue-Faye Ng, Xingzhu Chen, Joel Jie Foo, Mo Xiong, Wee-Jun Ong 2023, 47:  150-160.  DOI: 10.1016/S1872-2067(23)64417-1 Abstract ( 386 )   HTML ( 23 )   PDF (5742KB) ( 518 )   Supporting Information Solar-driven water splitting for green hydrogen production has been prospected as an auspicious technology to achieve sustainable energy generation by shifting towards renewable and zero-carbon emission fuels. Recently, N-rich C3N5 allotropes are emerging to surpass the intrinsic drawbacks of g-C3N4, which are the rapid recombination of photogenerated charge carriers and poor visible light absorption, resulting in low photocatalytic efficiency. In this study, density functional theory calculation was conducted on the pristine C3N5 and boron-doped C3N5 systems to study the effect of boron atom on the electronic and optical properties, as well as the hydrogen evolution reaction mechanism. The boron-dopants were introduced in C3N5 through substitutional or interstitial doping. It is indicated that the incorporation of boron atoms in the C3N5 matrix is thermodynamically favorable. A band gap narrowing of 0.6 eV was observed after the N3-site nitrogen atom was replaced by a boron atom (BN3-C3N5). Compared to pristine C3N5, the boron-dopant also reduced the reaction energies of potential determining step of the HER pathway in both acid and alkaline media through the Volmer-Tafel and Volmer-Heyrovsky mechanism. The Gibbs free energy of hydrogen adsorption (ΔGH*) of BN3-C3N5 (0.11 eV) is comparable to the benchmark Pt/C catalyst (-0.09 eV). These theoretical results allude to the elucidated catalytic performance of non-metal doped carbon nitrides that can be applied to future experimental and computational analysis.

Select

Metallic WO2-decorated g-C3N4 nanosheets as noble-metal-free photocatalysts for efficient photocatalysis Ning Li, Xueyun Gao, Junhui Su, Yangqin Gao, Lei Ge 2023, 47:  161-170.  DOI: 10.1016/S1872-2067(22)64210-4 Abstract ( 229 )   HTML ( 14 )   PDF (1946KB) ( 590 )   Supporting Information The introduction of a metallic cocatalyst is a good strategy for achieving a high carrier density and absorbing photons under wide-spectrum illumination. Herein, metallic WO2/g-C3N4 nanocomposites were designed and synthesized for the first time using a simple calcination method to enhance the photocatalytic performance. WO2/g-C3N4 exhibited significant photocatalytic properties: under visible light irradiation, 4 wt% WO2/g-C3N4 exhibited an RhB photocatalytic degradation of 96% in 120 min. Meanwhile, the H2 production rate of 4 wt% WO2/g-C3N4/3 wt% Pt was 2436.9 μmol g-1 h-1, which was 2.55 and 6.18 times higher than that of 3 wt% Pt/g-C3N4 (956.35 μmol g-1 h-1) and WO2/g-C3N4, respectively. Experimental tests and density functional theory calculations reveal that WO2 exhibits a metal-like performance with a narrow bandgap to capture electrons and hinders the recombination of photogenerated charge carriers at the interface of WO2/g-C3N4. Our study provides a new perspective for the rational design of metallic cocatalysts/semiconductors with highly efficient photocatalytic properties.

Select

Vinylene-linked covalent organic frameworks with manipulated electronic structures for efficient solar-driven photocatalytic hydrogen production Zhipeng Xie, Xiubei Yang, Pei Zhang, Xiating Ke, Xin Yuan, Lipeng Zhai, Wenbin Wang, Na Qin, Cheng-Xing Cui, Lingbo Qu, Xiong Chen 2023, 47:  171-180.  DOI: 10.1016/S1872-2067(23)64397-9 Abstract ( 368 )   HTML ( 18 )   PDF (4911KB) ( 644 )   Supporting Information Vinylene-linked covalent organic frameworks (COFs) are promising photocatalysts owing to their fully conjugated skeletons that facilitate charge carrier mobility. Constructing donor-acceptor (D-A) architectures could further enhance photoinduced charge generation and transport, thus promoting photocatalysis. Therefore, three D-A-type vinylene-linked COFs were fabricated via Knoevenagel polymerization for efficient photocatalysis. By varying the donor moieties from phenyl to 2,5-dimethylbenzene and 3,3'-dimethyl-1,1'-biphenyl in the skeletons, the light-harvesting, optical-bandgap, and charge-transfer properties of the COFs were precisely regulated. All three COFs exhibited attractive photocatalytic hydrogen evolution rates (HERs) upon visible-light irradiation, especially that fabricated using 2,4,6-trimethyl-1,3,5-triazine (TM) and 3,3'-dimethyl[1,1'-biphenyl]-4,4'-dicarboxaldehyde (DMA, TM-DMA-COF). TM-DMA-COF exhibited the strongest D-A interactions, excellent charge-carrier separation and transfer kinetics, and a reduced energy barrier for H2 formation. Thus, it afforded the highest HER of 4300 µmol h‒1 gcat‒1, surpassing those of most state-of-the-art COF photocatalysts. This study provides a simple and effective protocol for modulating the photocatalytic activities of COFs at the molecular level and an interesting insight into the relationship between structural design and photocatalytic performance.

Select

Co@CoO-catalyzed reductive amination driven by hydride-like NH2δ‒ species Wanjun Guo, Zhi-Qiang Wang, Shuang Xiang, Yaxuan Jing, Xiaohui Liu, Yong Guo, Xue-Qing Gong, Yanqin Wang 2023, 47:  181-190.  DOI: 10.1016/S1872-2067(22)64196-2 Abstract ( 157 )   HTML ( 12 )   PDF (4942KB) ( 405 )   Supporting Information Owing to the wide application of primary amines, their selective production via reductive amination has become a crucial research topic. Various metal-supported catalysts (Pt, Ru, Rh, Ir, Co, Ni, etc.) have been investigated, and metallic species have been recognized as active sites in recent years. Herein, we reveal for the first time that CoO species containing oxygen vacancies within a core-shell-structured Co@CoO catalyst accelerate the ammonolysis of Schiff bases, key intermediates in reductive amination, through NH3 dissociation to hydride-like NH2δ- species, delivering an excellent reductive amination performance. The catalyst is highly stable and was utilized in 10 catalytic cycles for the amination of biomass-derived cyclopentanone (CPO) to cyclopentylamine (CPA) without deactivation. Various computational models in combination with spectroscopic measurements indicated that this catalyst not only drives the dissociation of H2 to the active Hδ- species, but also enables the homolytic cleavage of NH3 to NH2δ-. D2 isotopic tracing experiments provided further evidence of the direct involvement of hydride-like NH2δ- species in Schiff base ammonolysis. Theoretical calculations verified the stable co-adsorption of Hδ- and NH2δ-, which allows the Schiff base to move freely on the surface of the CoO shell and participate extensively in molecular collisions, resulting in exceptional catalytic activity. This is the first study that demonstrates the potential of metal oxide catalysts for the production of primary amines via reductive amination.

Select

Engineering of a P450-based Kemp eliminase with a new mechanism Aitao Li, Qian Wang, Xitong Song, Xiaodong Zhang, Jian-Wen Huang, Chun-Chi Chen, Rey-Ting Guo, Binju Wang, Manfred T. Reetz 2023, 47:  191-199.  DOI: 10.1016/S1872-2067(23)64389-X Abstract ( 443 )   HTML ( 19 )   PDF (2176KB) ( 549 )   Supporting Information For three decades the biocatalytic version of the Kemp elimination of 5-nitro-benzisoxazole (1) has served as a forum for testing the creation of different artificial enzymes, the primary aim being to reveal mechanistic intricacies and to extend our understanding of enzymatic catalysis as such. In general, acid/base catalysis pertains, but recently a novel redox based mechanism was postulated when using P450-BM3 mutants as scaffolds. In the present study, we report an surprising discovery made upon employing new P450-BM3 variants generated by rational enzyme design, which points to the existence of a new and different redox based mechanism. X-ray structural data and theoretical analyses based on MD simulations and QM/MM calculations support this conclusion. The results of this study are of relevance in the human metabolism of therapeutic drugs and in redox mediated biosynthesis catalyzed by P450s.

Select

SCM-36 zeolite nanosheets applied in the production of renewable p-xylene from ethylene and 2,5-dimethylfuran Duozheng Ma, Xiangcheng Li, Chuang Liu, Caroline Versluis, Yingchun Ye, Zhendong Wang, Eelco T. C. Vogt, Bert M. Weckhuysen, Weimin Yang 2023, 47:  200-213.  DOI: 10.1016/S1872-2067(22)64200-1 Abstract ( 222 )   HTML ( 6 )   PDF (7978KB) ( 519 )   Supporting Information Zeolites as solid acid materials have played important roles in industrial catalysis. The attempts to obtain new zeolite framework structures and related chemical compositions have never stopped, and may expand the application thereof. Using renewable bioderived molecules as starting feedstocks would be of great help in building a more circular carbon cycle. However, zeolites have only shown limited efficiency in the conversion or production of bioderived chemicals. In this work, we report on the synthesis of a new aluminosilicate zeolite named SCM-36 (Sinopec Composite Material No. 36) using tetramethylammonium hydroxide (TMAOH) with the presence of hexadecylpyridinium bromide hydrate (C16PyBr) or octyltrimethylammonium chloride (OTMAC). The pore opening of this new zeolite material is about 0.6 nm, which is consistent with the size of 10 to 12 membered ring channel. SCM-36 possesses a nanoflower-like morphology with a thickness of ~20 nm. The SiO2/Al2O3 molar ratio of the SCM-36 material is ranging from 21.2 to 36.6, with most Al incorporated into the zeolite framework structure. The acid strength of SCM-36 is not strong, as confirmed by various techniques, including NH3-TPD, pyridine FT-IR, ex-situ confocal fluorescence microscopy and in-situ UV-Vis micro-spectroscopy. In the catalytic conversion of bio-derived 2,5-dimethylfuran (DMF) and ethylene into para-xylene (PX), H-SCM-36 zeolite showed better performance than the more traditional zeolites. The highest selectivity towards PX reached a value of ~93%. Besides, SCM-36 zeolite showed remarkable recyclability in the reaction.

Select

Synergy between single atoms and nanoclusters of Pd/g-C3N4 catalysts for efficient base-free CO2 hydro-genation to formic acid Eun Hyup Kim, Min Hee Lee, Jeehye Kim, Eun Cheol Ra, Ju Hyeong Lee, Jae Sung Lee 2023, 47:  214-221.  DOI: 10.1016/S1872-2067(22)64202-5 Abstract ( 226 )   HTML ( 7 )   PDF (22229KB) ( 657 )   Supporting Information In base-free CO2 hydrogenation to HCOOH over C3N4-supported Pd catalysts, a synergy between Pd single atoms and nanoclusters has been discovered by observing the highest catalytic activity when an optimum ratio of the two Pd states is present in the catalyst. It is demonstrated that Pd clusters are mainly involved in H2 activation by dissociative adsorption, while single atoms are more effective for CO2 activation. Thus, at an optimum single atom ratio (number of single atoms/number of single atoms + nanoclusters) of 41%, the catalyst shows the highest activity, which is superior to all Pd catalysts reported previously in the literature under the similar reaction conditions.

Select

Enantioselective synthesis of unprotected 2-quinolinone-based cyclic amino acids via sequential palladium-catalyzed asymmetric allylation/desymmetrization Qian Li, Yan Liu, Can Li 2023, 47:  222-228.  DOI: 10.1016/S1872-2067(23)64390-6 Abstract ( 212 )   HTML ( 7 )   PDF (945KB) ( 354 )   Supporting Information Chiral unprotected 3-amino-2-quinolinone and 2-quinolinone-based cyclic amino acids have been recognized as important scaffolds in the structures of various drugs and bioactive molecules. However, a direct asymmetric method for the synthesis of these structures remains elusive. In this study, we report a Pd(0)-catalyzed enantioselective sequential decarboxylative allylation/desymmetrization protocol. Various vinyl benzoxazinanones can be used as substrates to react with unprotected amino esters, affording enantioenriched 2-quinolinone-based cyclic amino acids with high enantioselectivities (up to 96% ee) and good diastereoselectivities (up to 15:1 dr). Moreover, the products could be successfully transformed to chiral 3-amino-2-quinolinone derivatives after treatment with aqueous HCl. Mechanistic studies revealed that the double-hydrogen-bond-directing effect between the enolate (2-aminomalonate) and π-allyl Pd(II) complex plays an important role in the control of regioselectivity, and the steric hindrance between tert-butyl group on the ligand and allyl group on the substrate is responsible for the high enantioselectivity.

Select

Ni nanoparticle coupled surface oxygen vacancies for efficient synergistic conversion of palmitic acid into alkanes Yan Zeng, Hui Wang, Huiru Yang, Chao Juan, Dan Li, Xiaodong Wen, Fan Zhang, Ji-Jun Zou, Chong Peng, Changwei Hu 2023, 47:  229-242.  DOI: 10.1016/S1872-2067(23)64401-8 Abstract ( 209 )   HTML ( 8 )   PDF (6910KB) ( 429 )   Supporting Information The catalytic transformation of renewable biomass oil (mainly comprising fatty acids and triglycerides) into high-value alkanes is a versatile technique, and Ni-based catalysts are considered to be the most suitable substitutes for precious metals. Ni nanoparticles supported on CeO2 carriers, prepared by hydrothermal synthesis (Ni/H-CeO2) with abundant oxygen vacancies, exhibited superior catalytic activity compared to precious metal catalysts. For the hydrodeoxygenation of palmitic acid, the Ni/H-CeO2 catalyst converted palmitic acid into pentadecane with a 94.8% selectivity under mild reaction conditions. The outstanding catalytic performance of Ni/H-CeO2 can be attributed to the synergistic effect between the Ni nanoparticles for activating hydrogen and the abundant oxygen vacancies for adsorbing oxygen from palmitic acid. The abundant oxygen vacancies of Ni/H-CeO2 improved the interaction between the Ni metal and CeO2 support, as confirmed by density functional theory calculations. Therefore, the abundant oxygen vacancies were more conducive to the dispersion of Ni, resulting in the formation of Ni nanoparticles, which enhanced the potential for hydrogen activation due to the increased number of exposed Ni and electronic effects. The high pentadecane selectivity was governed by small Ni nanoparticles. This study provides a novel strategy to obtain an efficient hydrodeoxygenation catalyst for converting biomass oil into biofuel.

Select

Photoelectrocatalytic reduction of CO2 catalyzed by TiO2/TiN nanotube heterojunction: Nitrogen assisted active hydrogen mechanism Yan Wei, Ruizhi Duan, Qiaolan Zhang, Youzhi Cao, Jinyuan Wang, Bing Wang, Wenrui Wan, Chunyan Liu, Jiazang Chen, Hong Gao, Huanwang Jing 2023, 47:  243-253.  DOI: 10.1016/S1872-2067(23)64395-5 Abstract ( 257 )   HTML ( 6 )   PDF (11971KB) ( 341 )   Supporting Information To address the over-emission of CO2, the construction of new heterojunction materials is a promising approach for the photoelectrocatalytic (PEC) conversion of CO2 into valuable chemicals. Herein, a series of heterojunctions of TiO2/TiN nanotube arrays were designed and fabricated by anodic oxidation of titanium plates, followed by in situ partial oxidation to form heterojunctions. The surface of the heterojunction with nitrogen instead of oxygen contained more active Ti3+ species, and the oxygen vacancies were able to harvest solar light and showed excellent performance in the PEC reduction of CO2. As a porous material, the TiO2/TiN nanotube supports good adsorption of CO2 as well as a confined space favoring C-C coupling. Operando Fourier transform infrared (FTIR) analysis revealed that the active species *COOḢ and *CHO were the major intermediates. Density functional theory (DFT) calculations revealed that the highly active hydrogen atoms could attach to the surface of the heterojunction to form Ti-H species with Ti3+, and the existence of nitrogen atoms could promote the migration of lattice oxygen to form new oxygen vacancies, which is conducive to the adsorption and coupling of CO2 and intermediates. The vibration frequency of Ti-H predicted by DFT calculations matches well with the operando FTIR observations. The PEC cell of Pd/R-TiO2/TiN-30|SCE|BiVO4 efficiently produced carbon-based chemicals at a rate of 115.9 μmol L-1 h-1 cm-2 with high selectivity for C2 products. The total efficiency of the PEC cell approached 6.0%, exceeding that of the plant cell by 0.4%. Isotopic labeling experiments of 13CO2 and H218O verified the elemental source and inferred the reaction pathway via highly active hydrogen.

Select

Co nanoparticles modified phase junction CdS for photoredox synthesis of hydrobenzoin and hydrogen evolution Meiyu Zhang, Kongming Li, Chunlian Hu, Kangwei Ma, Wanjun Sun, Xianqiang Huang, Yong Ding 2023, 47:  254-264.  DOI: 10.1016/S1872-2067(23)64393-1 Abstract ( 219 )   HTML ( 9 )   PDF (5959KB) ( 648 )   Supporting Information Coupling photocatalytic H2 production with organic synthesis attracts immense attention in the field of energy research through collecting the sustainable green energy and high value-added products. Although tremendous progress has been made towards devoting to the oxidation of benzyl alcohol, only very limited study can meet high selectivity of the C-C coupled products during the process of H2 evolution. Herein, the phase junction CdS (HC-CdS2) consisting of hexagonal CdS (H-CdS) with co-exposed facets of (001) and (101) and cubic CdS (C-CdS) was fabricated by fine tuning the proportion of cadmium and sulfur sources for photocatalytic H2 production and selective benzyl alcohol oxidation. The HC-CdS2 is able to maintain a robust H2 evolution rate of 11 mmol g-1 by loading cobalt as cocatalyst, which is 4.7 and 34 times higher than those for C-CdS/Co and HC-CdS2, respectively. Especially, the selectivity of hydrobenzoin elevated from 12% to 97% after loading Co on HC-CdS2 after light irradiation for 9 h. EPR and in situ DRIFTS tests indicated that the hydrogen atom from the C-H bond of benzyl alcohol was abstracted to form ·C7H8O free radical. Subsequently, the ·C7H8O free radical coupling yield hydrobenzoin as the final C-C coupling product by ameliorating charge separation resulted from the internal electric fields of facet junction and phase junction CdS and Schottky junction between CdS and Co. The strategy can be further extended to various aromatic alcohols and provide a reference for highly selective synthesis of high-added value chemicals coupled with H2 evolution.

Select

Hydrogenation of crotonaldehyde over ligand-capped Ir catalysts: Metal-organic interface boosts both activity and selectivity Yan-Wen Ye, Yi-Ming Hu, Wan-Bin Zheng, Ai-Ping Jia, Yu Wang, Ji-Qing Lu 2023, 47:  265-277.  DOI: 10.1016/S1872-2067(23)64399-2 Abstract ( 188 )   HTML ( 9 )   PDF (2946KB) ( 519 )   Supporting Information Ir nanoparticles (NPs) were synthesized via a colloidal method using tetradecyltrimethyl ammonium bromide (TTAB) as the ligand, and the supported Ir/BN catalysts were employed for selective hydrogenation of crotonaldehyde (CRAL). It was found that by proper thermal treatments, the TTAB-capped Ir NPs were very active and selective for the reaction. The Ir/BN catalyst calcined at 300 °C with surface TTAB residue gave a quasi-steady state turnover frequency (TOF) for crotyl alcohol (CROL) formation of 0.02 s-1 and a CROL selectivity of 94.4%, while that calcined at 500 °C with clean surface gave a TOF of 0.004 s-1 and a CROL selectivity of 56.2%. The Ir-TTAB interface was essential for the enhanced performance. In-situ IR spectra along with kinetic investigation revealed that TTAB improved CRAL adsorption and strengthened C=O adsorption, which accounted for high activity and selectivity. However, high coverage of TTAB on the Ir surface suppressed the H2 adsorption and consequently lowered the activity. Thus the findings provided useful information on the design of efficient catalysts for selective hydrogenation.