Unveiling the Mechanism of Glycerol Oxidation to Lactic Acid on Pt/Sn-MFI Zeolite:an In situ Solid-state NMR Study  

作　　者：SHEN Xueyuan QI Guodong LIANG Jiawei WANG Ruichen XU Jun DENG Feng 

机构地区：[1]National Centre for Magnetic Resonance in Wuhan,State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430071,P.R.China [2]University of Chinese Academy of Sciences,Beijing 100049,P.R.China

出　　处：《Chemical Research in Chinese Universities》2024年第6期935-942,共8页高等学校化学研究（英文版）

基　　金：supported by the National Key R&D Program of China(No.2022YFA1504500);the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0540000);the National Natural Science Foundation of China(Nos.22272185,22225205,22320102002,22127801,22161132028);the Natural Science Foundation of Hubei Province,China(No.2021CFA021);the Hubei International Scientific and Technological Cooperation Program,China(No.2022EHB021);the International Science&Technology Cooperation Base for Sustainable Catalysis and Magnetic Resonance,China(No.SH2303);the Young Top-notch Talent Cultivation Program of Hubei Province,China.

摘　　要：Heterogeneous glycerol(GLY)oxidation offers a promising route for the production of lactic acid(LA);a key monomer in biodegradable bioplastics.However,the specific reaction pathways remain poorly understood.This study presents a mechanistic investigation of GLY oxidation to LA using Pt/Sn-MFI catalysts.Characterizations via DR-UV-Vis spectroscopy,119Sn NMR,and TEM reveal the formation of zeolite framework Sn and well-dispersed Pt nanoparticles in Pt/Sn-MFI.The Lewis acidity of framework Sn in MFI zeolite is confirmed through 31P NMR probe techniques.GLY conversion and LA selectivity correlate strongly with framework Sn concentration and the presence of Pt nanoparticles.In situ 13C solid-state NMR experiments,complemented by two-dimensional 13C correlation NMR,allow real-time monitoring of GLY conversion and identification of various mobile and rigid(surface-adsorbed)species.Results indicate that GLY preferentially transforms to LA via a dihydroxyacetone(DHA)intermediate,facilitated by the Pt-Sn synergistic effect.However,accumulation of surface-adsorbed LA on Sn sites promotes consecutive oxidation of GLY to glyceric acid,tartaric acid,and ultimately CO_(2).

关 键 词：Biomass conversion In situ NMR Glycerol oxidation ZEOLITE Reaction mechanism 

分 类 号：O64[理学—物理化学]