CO2甲烷化:高低温活性和抗烧结的Ni/CaO-ZrO2-Al2O3催化剂OA

Ni/Al2O3 is regarded as one of the most promising catalysts for industrial application in CO2 methanation,but is still plagued by issues of inadequate low-temperature activity and thermal sintering.In response to these challenges,an Ni/CaO-ZrO2-Al2O3 catalyst with high low-temperature activity and robust high-temperature sintering resistance was prepared by introducing Ca and Zr promoters.Under the reaction conditions of 250℃ and a space velocity of 30000 mL/(g·h),the CO2 conversion and methane space-time yield reached 96％and 257.5 mmol/(gh),respectively.In addition,the Ca-Zr dual-promoted Ni/CaO-ZrO2-Al2O3 catalyst exhibited a smaller increase in the Ni particle size and less activity loss than the Ca-promoted catalyst in a 200 h aging test at 600℃.The Ca and Zr promoters can not only improve the Ni dispersion but also enhance the surface basicity,resulting in excellent low-temperature activity.Moreover,the Zr promoter suppresses the transformation of Ca species into CaCO3 through solid-phase reaction under operating conditions,thereby inhibiting Ni sintering and ensuring high-temperature stability.This work provides a new promoter design strategy for the development of high-performance Ni-based catalysts for CO2 methanation.