Subnanometer molybdenum oxide-stabilized platinum nanocatalysts enable efficient hydrogen production from methylcyclohexane

doi:10.1016/S1872-2067(25)64829-7

Abstract

Abstract:

Methylcyclohexane (MCH) stands out as a leading liquid organic hydrogen carrier (LOHC) due to its favorable hydrogen storage capacity and transportability. Despite its potential, advancing catalysts that combine high efficiency, cost-effectiveness, and durability for MCH dehydrogenation to produce hydrogen remains a critical challenge hindering large-scale industrial deployment. Herein, we report the synthesis of highly dispersed and stable bimetallic Pt-MoO_x nanoparticles immobilized on γ-Al₂O₃. The introduction of MoO_x species significantly improves the stability of Pt and results in a high toluene (TOL) selectivity of 99.8 % with MCH conversion of 99.5% and a high hydrogen evolution rate of 470.5 mmol·g_Pt^-1·min^-1 at 340 °C. Moreover, the optimal catalyst exhibits a remarkable long-term stability, with no evident loss of activity in 140-h dehydrogenation reaction at a weight hourly space velocity of 11.7 h^-1. Through detailed in-situ structure analyses, it was revealed that the introduction of subnanometer MoO_x species facilitates the generation of ultrafine Pt nanoparticles with improved resistance to sintering, resulting in enhanced catalytic activity and durability of the noble metal. Furthermore, in-situ spectroscopic characterization demonstrates the positively charged Pt^δ⁺ species promote the rapid desorption of TOL products. The excellent catalytic performance including high conversion and selectivity and superior stability offers great opportunities for their practical applications in LOHC technologies.

Key words: Liquid organic hydrogen carriers, Hydrogen production, Methylcyclohexane, Dehydrogenation, Pt-Mo catalyst

Shenghui Zhou, Zheng Wang, Voon Huey Lim, Chi Cheng Chong, Hossein Akhoundzadeh, Chao Wu, Mohammadreza Kosari, Shibo Xi, Markus Kraft, Rong Xu. Subnanometer molybdenum oxide-stabilized platinum nanocatalysts enable efficient hydrogen production from methylcyclohexane[J]. Chinese Journal of Catalysis, 2026, 80: 347-357.

×
share this article

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.cjcatal.com/EN/10.1016/S1872-2067(25)64829-7

https://www.cjcatal.com/EN/Y2026/V80/I1/347

Figures/Tables 7

Scheme 1. Schematic diagram of MCH as LOHCs.

Fig. 1. (a) Schematic illustration of the targeted synthesis of PtMo/Al2O3. TEM image (b) and HAADF STEM (c) images of 2.4Pt4Mo/Al2O3. Particle size distribution (d) and EDX line scanning (e) of 2.4Pt4Mo/Al2O3. (f) EDX elemental mapping of 2.4Pt4Mo/Al2O3.

Fig. 2. XRD patterns (a), N2 adsorption-desorption isotherms (b), corresponding pore size distribution diagram (c), XPS spectra of survey scan (d), Pt 4d spectra (e) and Mo 3d spectra (f) of different samples. The metal loaded samples were pretreated in H2 at 380 °C for 3 h before characterization.

Fig. 3. Pt L3-edge XANES spectra (a), FT-EXAFS curves (b) and corresponding fits at the Pt K-edge (c), and WT-EXAFS (d) of various samples.

Fig. 4. Catalytic performance evaluation. Time on stream of MCH conversion (a) and TOL selectivity (b) over 0.7Pt1Mo/Al2O3 and 0.7Pt/Al2O3. Reaction conditions: MCH flowrate (25 °C, 1 atm) = 0.05 mL/min, WHSV = 11.6 h-1, and reaction temperature = 370 °C. Time on stream of MCH conversion (c) and TOL selectivity (d) over 2.4Pt4Mo/Al2O3, 2.4Pt/Al2O3, 4Mo2.4Pt/Al2O3, 2.4Pt7Mo/Al2O3, 2.4Pt1Mo/Al2O3. Reaction conditions: MCH flowrate (25 °C, 1 atm) = 0.1 mL/min, WHSV = 23.1 h-1, and reaction temperature = 340 °C. No co-feeding of H2 or other gases for all reactions.

Fig. 5. (a) In-situ DRIFTS of CO adsorption on 2.4Pt4Mo/Al2O3 and 2.4Pt/Al2O3. (b) H2-TPR of 2.4Pt4Mo/Al2O3 and 2.4Pt/Al2O3. (c) NH3-TPD of 2.4Pt4Mo/Al2O3 and 2.4Pt/Al2O3. (d) Pyridine-adsorbed FT-IR spectrum of 2.4Pt4Mo/Al2O3. MCH-TPSR of 2.4Pt4Mo/Al2O3 (e) and 2.4Pt/Al2O3 (f).

Fig. 6. DRIFTS of TOL-adsorption (a,c) and desorption (b,d) over 2.4Pt4Mo/Al2O3 (a,b) and 2.4Pt/Al2O3 (c,d). (e) Corresponding peak intensities of TOL during adsorption and desorption. (f) Catalytic performance comparison between 2.4Pt4Mo/Al2O3 and TOL adsorbed 2.4Pt4Mo/Al2O3.

References

[1]	T. He, P. Pachfule, H. Wu, Q. Xu, P. Chen, Nat. Rev. Mater., 2016, 1, 16059.
[2]	M. D. Allendorf, V. Stavila, J. L. Snider, M. Witman, M. E. Bowden, K. Brooks, B. L. Tran, T. Autrey, Nat. Chem., 2022, 14, 1214-1223.
[3]	R. Sang, Z. Wei, Y. Hu, E. Alberico, D. Wei, X. Tian, P. Ryabchuk, A. Spannenberg, R. Razzaq, R. Jackstell, J. Massa, P. Sponholz, H. Jiao, H. Junge, M. Beller, Nat. Catal., 2023, 6, 543-550.
[4]	P. Preuster, C. Papp, P. Wasserscheid, Acc. Chem. Res., 2017, 50, 74-85.
[5]	T. He, Q. Pei, P. Chen, J. Energy Chem., 2015, 24, 587-594.
[6]	X. Li, D. Ma, X. Bao, Chin. J. Catal., 2008, 29, 259-263.
[7]	H. Wang, K. Li, M. Lopez-Haro, C. Marini, Z. He, M. Gao, L. Zhang, L. Liu, J. Am. Chem. Soc., 2025, 147, 21789-21802.
[8]	L. Zhang, L. Liu, Z. Pan, R. Zhang, Z. Gao, G. Wang, K. Huang, X. Mu, F. Bai, Y. Wang, W. Zhang, Z. Cui, L. Li, Nat. Energy, 2022, 7, 1042-1051.
[9]	F. Valentini, A. Marrocchi, L. Vaccaro, Adv. Energy Mater., 2022, 12, 2103362.
[10]	Y. Deng, Y. Guo, Z. Jia, J.-C. Liu, J. Guo, X. Cai, C. Dong, M. Wang, C. Li, J. Diao, Z. Jiang, J. Xie, N. Wang, H. Xiao, B. Xu, H. Zhang, H. Liu, J. Li, D. Ma, J. Am. Chem. Soc., 2022, 144, 3535-3542.
[11]	Y. Wang, H. Yu, Y. He, S. Xiang, X. Qin, L. Yang, J. Chen, Y. Si, J. Zhang, J. Diao, N. Wang, M. Peng, D. Ma, H. Liu, Angew. Chem. Int. Ed., 2025, 64, e202415542.
[12]	R. A. Jagtap, Y. Nishioka, S. M. Geddis, Y. Irie, T. Takanashi, R. Adachi, A. Yamakata, M. Fuki, Y. Kobori, H. Mitsunuma, M. Kanai, Nat. Commun., 2025, 16, 428.
[13]	Y.-Q. Zou, N. von Wolff, A. Anaby, Y. Xie, D. Milstein, Nat. Catal., 2019, 2, 415-422.
[14]	H. Wu, H. Wang, Y. Lv, Y. Wu, Y. Wang, Q. Luo, Y. Hui, L. Liu, M. Zhang, K. Hou, L. Li, J. Zeng, W. Dai, L. Wang, F.-S. Xiao, Angew. Chem. Int. Ed., 2025, 64, e202420306.
[15]	Z. He, K. Li, T. Chen, Y. Feng, E. Villalobos-Portillo, C. Marini, T. W. B. Lo, F. Yang, L. Zhang, L. Liu, Nat. Commun., 2025, 16, 92.
[16]	L. Chen, P. Verma, K. Hou, Z. Qi, S. Zhang, Y.-S. Liu, J. Guo, V. Stavila, M. D. Allendorf, L. Zheng, M. Salmeron, D. Prendergast, G. A. Somorjai, J. Su, Nat. Commun., 2022, 13, 1092.
[17]	Q.-L. Zhu, Q. Xu, Energy Environ. Sci., 2015, 8, 478-512.
[18]	M. Peng, C. Li, H. Meng, X. Tang, M. Wang, J. Zhang, J. Xie, Q. Zhang, F. Tong, H. Tian, H. Wang, L. Song, H. Liu, S. Dai, G. Sun, D. Ma, Angew. Chem. Int. Ed., 2025, 64, e202424816.
[19]	Y. Kwak, Y.-J. Lee, S. Moon, K. Lee, S. Ramadhani, E.-R. On, C.-I. Ahn, S.-J. Hwang, H. Sohn, H. Jeong, S. W. Nam, C. W. Yoon, Y. Kim, Angew. Chem. Int. Ed., 2025, 64, e202417598.
[20]	Y. Tuo, Y. Meng, Q. Lu, Q. Wang, F. Jia, Y. Zhou, X. Feng, J. Zhang, X. Duan, D. Chen, AlChE. J., 2023, 69, e18149.
[21]	C. Lin, B. C. S. Lee, U. Anjum, A. M. Prabhu, N. Chaudhary, R. Xu, T. S. Choksi, Appl. Catal. B, 2025, 371, 125192.
[22]	J. Gao, N. Li, D. Zhang, S. Zhao, Y. Zhao, Int. J. Hydrogen Energy, 2024, 85, 865-880.
[23]	M.-J. Zhou, Y. Miao, Y. Gu, Y. Xie, Adv. Mater., 2024, 36, 2311355.
[24]	A. Oda, K. Ichihashi, Y. Yamamoto, T. Ohtsu, W. Shi, K. Sawabe, A. Satsuma, J. Mater. Chem. A, 2024, 12, 22655-22667.
[25]	N. Boufaden, R. Akkari, B. Pawelec, J. L. G. Fierro, M. S. Zina, A. Ghorbel, J. Mol. Catal. A, 2016, 420, 96-106.
[26]	Y. Nakaya, A. Okada, S. Furukawa, JACS Au, 2025, 5, 1956-1964.
[27]	Y. Meng, Q. Sun, T. Zhang, J. Zhang, Z. Dong, Y. Ma, Z. Wu, H. Wang, X. Bao, Q. Sun, J. Yu, J. Am. Chem. Soc., 2023, 145, 5486-5495.
[28]	T. Toyao, S. Kayamori, Z. Maeno, S. M. A. H. Siddiki, K.-I. Shimizu, ACS Catal., 2019, 9, 8187-8196.
[29]	S. Mine, T. Yamaguchi, K. W. Ting, Z. Maeno, S. M. A. H. Siddiki, K. Oshima, S. Satokawa, K.-I. Shimizu, T. Toyao, Catal. Sci. Technol., 2021, 11, 4172-4180.
[30]	K. Kon, T. Toyao, W. Onodera, S. M. A. H. Siddiki, K.-I. Shimizu, ChemCatChem, 2017, 9, 2822-2827.
[31]	A. S. Touchy, S. M. A. Hakim Siddiki, W. Onodera, K. Kon, K.-I. Shimizu, Green Chem., 2016, 18, 2554-2560.
[32]	P.-P. Zhao, J. Chen, H.-B. Yu, B.-H. Cen, W.-Y. Wang, M.-F. Luo, J.-Q. Lu, J. Catal., 2020, 391, 80-90.
[33]	M. Niwa, K. Suzuki, N. Katada, T. Kanougi, T. Atoguchi, J. Phys. Chem. B, 2005, 109, 18749-18757.
[34]	N. Katada, M. Niwa, Catal. Surv. Asia, 2004, 8, 161-170.
[35]	S. Van Minnebruggen, K.Y. Cheung, T. De Baerdemaeker, N. Van Velthoven, M. Degelin, G. O'Rourke, H. Toyoda, A. Iemhoff, I. Muller, A.-N. Parvulescu, T. Mattke, J. Ferbitz, Q. Wu, F.-S. Xiao, T. Yokoi, N. Bottke, D. E. De Vos, Chin. J. Catal., 2024, 62, 124-130.
[36]	S. Zhou, F. Dai, Z. Xiang, T. Song, D. Liu, F. Lu, H. Qi, Appl. Catal. B, 2019, 248, 31-43.
[37]	S. Zhou, F. Dai, Y. Chen, C. Dang, C. Zhang, D. Liu, H. Qi, Green Chem., 2019, 21, 1421-1431.
[38]	S. Zhou, K. You, H. Gao, R. Deng, F. Zhao, P. Liu, Q. Ai, H. Luo, Mol. Catal., 2017, 433, 91-99.
[39]	C. Jiang, X. Chang, X. Wang, Z.-J. Zhao, J. Gong, Chem. Sci., 2022, 13, 7468-7474.
[40]	I. Badran, N. Sahar Riyaz, A. M. Shraim, N. N. Nassar, Comput. Theor. Chem., 2022, 1211, 113689.
[41]	J. C. Yori, C. L. Pieck, J. M. Parera, Catal. Lett., 2000, 64, 141-146.