Semi-quantitative design of synergetic surficial/interfacial sites for the semi-continuous oxidation of glycerol  

作　　者：Mingyu Gao Pengfei Yang Xinyi Zhang Yani Zhang Dianqing Li Junting Feng 

机构地区：[1]State Key Laboratory of Chemical Resource Engineering,Beijing University of Chemical Technology,Beijing,100029,China [2]Beijing Engineering Center for Hierarchical Catalysts,Beijing University of Chemical Technology,Beijing,100029,China

出　　处：《Fundamental Research》2022年第3期412-421,共10页自然科学基础研究（英文版）

基　　金：This work was supported by the National Natural Science Foundation(Grants No.22022801,21878016);the National Key Research and Development Program of China(Grant No.2017YFA0206804);Fundamental Research Funds for the Central Universities.

摘　　要：Qualitatively identifying the dominant catalytic site for each step of a semi-continuous reaction and semi-quantitatively correlating such different sites to the catalytic performance is of great significance toward the integration of multiple well-optimized sites on a heterogeneous catalyst.Herein,a series of structurally defined TiO_(x)-based catalysts were synthesized to provide a feasible approach to investigate the aforementioned issues using the semi-continuous oxidation of glycerol as a model reaction.Detailed investigations have verified the simultaneous presence of two kinds of Pt active sites:1)Negatively charged Pt bound to the oxygen vacancies of modified TiO_(x)in the form of Pt^(δ−)-O_(v)-Ti^(3+) sites and 2)metallic Pt(Pt_(0)site)located away from the inter-face.Meanwhile,the proportion of surficial and interfacial sites varies over this series of catalysts.Combined in situ FTIR experiments revealed that the reaction network was well-tuned via a site cooperation mechanism:The surficial Pt_(0)sites dissociatively adsorb the OH group of glycerol with a monodentate bonding geometry and the Pt^(δ−)-O_(v)-Ti^(3+) sites dissociate the C=O bond of the aldehyde group in a bidentate form.Furthermore,CO-FTIR spectroscopy confirmed a correlation between the reaction rate/product selectivity and the fraction of surficial/interfacial sites.A rational proportion of surficial and interfacial sites is key to enabling a high yield of glyceric acid.The most active catalyst with 32%surface sites and 68%interfacial sites exhibited 90.0%glycerol conversion and 68.5%GLYA selectivity.These findings provide a deeper understanding of the structure-activity relationships using qualitative identification and semi-quantitative analysis.

关 键 词：Synergistic effect Surficial sites Interfacial sites Semi-continuous reactions Semi-quantitative analysis 

分 类 号：O64[理学—物理化学]