摘要
化学工业生产中,用氢气为还原剂,通过选择性加氢可以制备多种重要化学品。5-羟甲基糠醛是重要的生物质基平台化合物,而5-甲基糠醛是用途广泛的化学品。由5-羟甲基糠醛加氢得到5-甲基糠醛是一条非常理想的路径,但是选择性活化C―OH非常困难。本文设计并制备了Pt@PVP/Nb_(2)O_(5)(PVP:聚乙烯吡咯烷酮)催化剂,该催化体系巧妙地结合了位阻效应、氢溢流和催化剂界面的电子效应,系统研究了该催化剂对5-羟甲基糠醛选择性加氢制备5-甲基糠醛催化性能,在最优条件下,5-甲基糠醛的选择性可达92%。利用密度泛函理论计算研究了5-羟甲基糠醛选择性加氢制备5-甲基糠醛反应路径。
Selective hydrogenation is a vital class of reaction.Various unsaturated functional groups in organic compounds,such as aromatic rings,alkynyl(C≡C),carbonyl(C=O),nitro(―NO_(2)),and alkenyl(C=C)groups,are typical targets in selective hydrogenation.Therefore,selectivity is a key indicator of the efficiency of a designed hydrogenation reaction.5-(Hydroxymethyl)furfural(HMF)is an important platform compound in the context of biomass conversion,and recently,the hydrogenation of HMF to produce fuels and other valuable chemicals has received significant attention.Controlling the selectivity of HMF hydrogenation is paramount because of the different reducible functional groups(C=O,C―OH,and C=C)in HMF.Moreover,the exploration of new routes for hydrogenating HMF to valuable chemicals is becoming attractive.5-Methylfurfural(MF)is also an important organic compound;thus,the selective hydrogenation of HMF to MF is an essential synthetic route.However,this reaction has challenging thermodynamic and kinetic aspects,making it difficult to realize.Herein,we propose a strategy to design a highly efficient catalytic system for selective hydrogenation by exploiting the synergy between steric hindrance and hydrogen spillover.The design and preparation of the Pt@PVP/Nb2O5 catalyst(PVP=polyvinyl pyrrolidone;Nb2O5=niobium(V)oxide)were also conducted.Surprisingly,HMF could be converted to MF with 92%selectivity at 100%HMF conversion.The reaction pathway was revealed through the combination of control experiments and density functional theory calculations.Although PVP blocked HMF from accessing the surface of Pt,hydrogen(H2)could be activated on the surface of Pt due to its small molecular size,and the activated H_(2) could migrate to the surface of Nb_(2)O_(5) through a phenomenon called H2 spillover.The Lewis acidic surface of Nb2O5 could not adsorb the C=O group but could adsorb and activate the C―OH group of HMF;therefore,when HMF was adsorbed on Nb2O5,the C―OH groups were hydrogenated by the spilled over H2 to form MF.The h
作者
李少鹏
杜靖
张彬
刘艳贞
梅清清
孟庆磊
董明华
杜鹃
赵志娟
郑黎荣
韩布兴
赵美廷
刘会贞
Shaopeng Li;Jing Du;Bin Zhang;Yanzhen Liu;Qingqing Mei;Qinglei Meng;Minghua Dong;Juan Du;Zhijuan Zhao;Lirong Zheng;Buxing Han;Meiting Zhao;Huizhen Liu(Beijing National Laboratory for Molecular Sciences,CAS Key Laboratory of Colloid and Interface and Thermodynamics,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China;School of Chemical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Molecular Aggregation Science,Tianjin University,Tianjin 300072,China;.4 Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China;.5 Physical Science Laboratory,Huairou National Comprehensive Science Center,Beijing 101407,China.)
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2022年第10期65-72,共8页
Acta Physico-Chimica Sinica
基金
国家重点研发计划(2017YFA0403003,2017YFA0403101)
国家自然科学基金(21871277,21603235,21403248,21905195)
中国博士后科学基金(2021M702435)
北京市科技计划(Z191100007219009)资助。
关键词
生物质
5-羟甲基糠醛
选择性加氢脱氧反应
空间位阻
氢溢流
Biomass
5-Hydroxymethylfurfural
Selective hydrodeoxygenation
Steric hindrance
Hydrogen spillover