催化学报 ›› 2026, Vol. 87: 327-341.DOI: 10.1016/S1872-2067(26)65104-2

• 论文 • 上一篇    下一篇

通过油溶性多金属氧酸盐衍生的单层NiMoS催化剂实现酯的选择性C−O键断裂

许崇正, 邸浩平, 孙风跃, 鲍文静, 巨延伟, 闫登伟, 岳长乐, 徐艺源, 赵蕴秀, 王硕, 王继乾, 卢玉坤*()   

  1. 中国石油大学(华东)化学化工学院, 重质油全国重点实验室, 山东青岛 266580
  • 收稿日期:2025-11-24 接受日期:2026-01-26 出版日期:2026-08-18 发布日期:2026-06-24
  • 通讯作者: *电子信箱: lyk@upc.edu.cn (卢玉坤).
  • 作者简介:1共同第一作者.
  • 基金资助:
    国家自然科学基金(22478435);国家自然科学基金(U22B20144);山东省自然科学基金(ZR2023MB004);山东省泰山学者计划(tsqn202408093);中央高校基本科研业务费专项资金(23CX03001A);中央高校基本科研业务费专项资金(25CX04019A)

Achieving selective C−O bond cleavage of esters over monolayer NiMoS catalysts derived from oil-soluble polyoxometalates

Chongzheng Xu, Haoping Di, Fengyue Sun, Wenjing Bao, Yanwei Ju, Dengwei Yan, Changle Yue, Yiyuan Xu, Yunxiu Zhao, Shuo Wang, Jiqian Wang, Yukun Lu*()   

  1. State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong, China
  • Received:2025-11-24 Accepted:2026-01-26 Online:2026-08-18 Published:2026-06-24
  • About author:1Contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(22478435);National Natural Science Foundation of China(U22B20144);Shandong Provincial Natural Science Foundation(ZR2023MB004);Taishan Scholars Program of Shandong Province(tsqn202408093);Fundamental Research Funds for the Central Universities(23CX03001A);Fundamental Research Funds for the Central Universities(25CX04019A)

摘要:

通过植物油或脂肪酸催化加氢脱氧(HDO)制取烃类燃料, 是生产可持续生物燃料、从根本上缓解化石燃料环境污染的有效途径. 然而, 传统硫化NiMo催化剂面临两大瓶颈: (1) 金属前驱体硫化过程中易烧结聚集, 导致活性位点密度显著降低; (2) Ni、Mo前驱体相互作用弱, 难以形成高活性NiMoS协同中心. 这些问题常引发C−C键过度裂解, 不仅造成大气污染物排放, 也降低了原子经济性. 因此, 为实现高效C−O键断裂, 发展具有高活性位点密度和高效NiMo协同作用的催化剂至关重要.

本文采用表面活性剂包覆(NH4)4[NiMo6O24H6](NiMo6)多金属氧酸盐(POMs), 合成了油溶性前驱体NiMo6-DODA, 并基于此原位构建了超分散单层NiMoS催化剂, 用于脂肪酸酯的HDO反应. 通过系统的表征与实验研究, 深入探究了催化剂在HDO反应过程中的构效关系. X-射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、核磁共振氢谱及热重分析证实NiMo6-DODA是由烷基链包裹POMs内核构成. 接触角测试和高分辨透射电镜(HRTEM)结果表明, “表面活性剂壳层”确保了其具有较好的疏水性, 使NiMo6 POMs在甲苯中实现均相单分散. XRD、拉曼光谱和HRTEM结果表明, 硫化产物S-NiMo6-DODA主要呈现高度分散的小尺寸单层MoS2结构. 这归因于硫化过程中烷基链逐渐牺牲分解, 其空间位阻效应有效抑制了MoS2纳米片的聚集生长, 从而充分暴露了活性位点. 同时, H2程序升温还原证实Ni与Mo的原子级接触促进了Mo物种的还原. X-射线光电子能谱和CO吸附FT-IR结果表明, 结构明确的“POMs核心”确保了Ni促进的NiMoS活性相占主导地位, 这种设计优化了酯类分子在NiMo催化剂上的吸附构型, 促使反应路径向HDO转变. 吡啶吸附FT-IR和电子顺磁共振谱结果进一步揭示NiMo协同作用引入了丰富的边缘硫空位, 有效促进氧原子吸附并加速C−O键断裂. 球差扫描透射电镜结果证实了Ni金属掺杂进入MoS2的边缘晶格, 并促进了S空位的形成. 催化性能测试结果表明, 通过反应条件的优化, 在低催化剂用量条件下NiMo6-DODA实现了棕榈酸甲酯100%的转化率和100%的烷烃选择性, 其中正十六烷(C16)选择性高达94.2%, 显著优于商用油溶性前驱体(69.8%). 该催化剂在多种长链脂肪酸底物、多次反应循环以及真实棕榈油的无溶剂转化中均表现出优异的高活性和高选择性稳定性. 通过FT-IR谱捕捉反应中间体, 并结合动力学和热力学分析, 发现棕榈酸甲酯倾向于快速氢化为十六醇, 这是实现高效HDO选择性的关键步骤. 推测反应机理如下: S-NiMo6-DODA丰富的硫空位优先吸附并活化棕榈酸甲酯的酯基氧原子. 同时, 催化剂边缘活性位点活化氢气, 并在该位点上将吸附活化的棕榈酸甲酯氢解为棕榈酸. 生成的棕榈酸以及可能存在的十六醛中间体通过Ni-Mo协同位点上形成的η2(C,O)-醛吸附构型被迅速加氢转化为十六烷醇. 十六烷醇最终在催化剂的酸性位点及金属位点上脱氧, 生成无碳损失的C16烷烃.

综上, 本研究基于预组装结合牺牲硫化的策略, 成功制备了超分散单层NiMoS催化剂, 实现酯的高选择性加氢脱氧. 该策略通过最大化暴露活性位点并精准调控酯类吸附构型, 为设计能够高稳定性、高选择性催化脂肪酸酯C−O键断裂的HDO催化剂提供了一条简单有效的途径.

关键词: 加氢脱氧, 油溶性催化剂, 多金属氧酸盐, NiMoS活性相, 单层二硫化钼

Abstract:

Sulfided NiMo catalysts can effectively hydrogenate oxygen-rich bio-oils into high quality hydrocarbon fuels. However, precisely controlling the cleavage of C−O bonds remains challenging. Here, we synthesized an oil-soluble precursor NiMo6-DODA by encapsulating the polyoxometalates (POMs) (NH4)4[NiMo6O24H6] (NiMo6) with surfactants, followed by in-situ construction of an ultra-dispersed monolayer NiMoS catalyst. The “surfactant shell” of the precursor ensured its homogeneous dispersion in the oil phase, while gradually sacrificing and decomposing during the sulfidation to mitigate the aggregation of the MoS2 nanosheets. Meanwhile, the well-defined “POMs core” established an atomic-level Ni-Mo proximity, ensuring the dominance of the Ni-promoted MoS2 active phase. This design not only altered the adsorption configuration of esters on the NiMo catalyst but also introduced abundant edge sulfur vacancies to promote oxygen atom adsorption and accelerate C−O bond cleavage. The results showed that NiMo6-DODA achieved 100% conversion of methyl palmitate and 100% alkane selectivity under low catalyst loading conditions. Notably, the selectivity for n-hexadecane reached 94.2%, significantly surpassing that obtained with a commercial oil-soluble precursor (69.8%). Furthermore, the catalyst maintained high activity across multiple reaction cycles and in the solvent-free conversion of real bio-oils. This strategy of pre-assembly combined with sacrificial sulfidation provides a simple and effective route for designing hydrodeoxygenation catalysts that enable precise control over ester C−O bond cleavage.

Key words: Hydrodeoxygenation, Oil-soluble catalyst, Polyoxometalates, NiMoS Active phases, Monolayer MoS2