摘要
探讨了载体对铟基催化剂上CO2加氢动力学的影响。通过浸渍法制备了不同载体的负载型In基催化剂,仅ⅣB族元素(Ti,Zr,Hf)氧化物负载的In基催化剂表现出明显的CO2加氢活性,其中In1/HfO2和In1/ZrO2催化剂具有较高的甲醇选择性,而In1/TiO2催化剂主要起催化逆水气变换反应的作用。通过稳态动力学、高压原位漫反射红外和程序升温实验等动力学手段,证明反应条件下In1/ZrO2和In1/HfO2上的关键表面反应中间体是甲酸盐与甲氧基,甲醇主要通过表面甲酸盐的逐步加氢生成。In1/HfO2具有最强的氢解离与加氢能力,因此最有利于甲醇合成。In1/TiO2在CO2加氢中表面无明显含碳中间物种,高CO选择性可能与界面氧空缺位点促进redox循环以及甲酸盐中间体分解相关。
In this work,the effect of support materials on the kinetic behaviors of indium-based catalysts in carbon dioxide hydrogenation was studied.A series of supported indium-based catalysts were prepared and tested.Only group Ⅳ B metal (Ti,Zr and Hf) oxide supported indium-based catalysts had substantial catalytic activity. Particularly,In1/HfO2 and In1/ZrO2 catalysts showed high methanol selectivity,while In1/TiO2 mainly catalyzed the reverse water-gas shift reaction.Steady-state kinetics,in-situ diffuse reflectance infrared Fourier transform spectroscopy and temperature-programmed experiments indicate that the key surface reaction intermediate over In1/ HfO2 and In1/ZrO2 are formate and methoxy species,and methanol is produced via stepwise hydrogenation of the surface formate.In1/HfO2 possesses the strongest hydrogen splitting and hydrogenation ability,thus favoring methanol synthesis.Over In1/TiO2,no significant surface carbonaceous species was detected under reaction conditions.The improved CO production might be related to interfacial oxygen defects facilitating the redox cycle and decomposition of formate intermediate.
作者
曹晨熙
陈天元
丁晓旭
黄海
徐晶
韩一帆
CAO Chenxi;CHEN Tianyuan;DING Xiaoxu;HUANG Hai;XU Jing;HAN Yifan(State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2019年第10期3985-3993,共9页
CIESC Journal
基金
国家重点研发计划项目(2018YFB0605803)
国家自然科学基金项目(21808058)
上海市青年科技英才扬帆计划项目(18YF1406100)
关键词
二氧化碳
催化剂
动力学
甲醇合成
原位红外
程序升温实验
carbon dioxide
catalysts
kinetics
methanol synthesis
in-situ DRIFTS
temperature-programed experiments
