CaH2-promoted activity of Ni-carbonate interface for CO_(2) methanation  

作　　者：Jin-Peng Wang Guo-Cui Mao Hui-Lin Jiang Bao-Xia Dong Yun-Lei Teng 

机构地区：[1]School of Chemistry and Chemical Engineering,Yangzhou University,Yangzhou 225002,Jiangsu,China

出　　处：《Journal of Energy Chemistry》2025年第1期522-532,共11页能源化学(英文版)

基　　金：National Natural Science Foundation of China (Nos. 22371244 and 21573192);Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_3463)。

摘　　要：Transition metal-carbonate interfaces often act as active sites in heterogeneous catalytic reactions.The interface between transition metal and metal carbonate exhibits a dynamic equilibrium during the CO_(2)hydrogenation reaction,involving surface carbonate hydrogenation and CO_(2)chemisorption.Nonetheless,there have been few reports on engineering the activity of the interface between transition metal and alkaline earth metal carbonate for catalytic CO_(2)conversion.This work demonstrated that the incorporation of CaH_(2)in Ni/CaCO_(3)enhances the CO_(2)methanation activity of the catalysts.The CO_(2)conversion for Ni/CaH_(2)-CaCO_(3)reached 68.5%at 400°C,which was much higher than that of the Ni/CaCO_(3)(31.6%) and Ni/CaH_(2)-CaO (42.4%) catalysts.Furthermore,the Ni/CaH_(2)-CaCO_(3)catalysts remained stable during the stability test for 24 h at 400°C and 8 bar.Our research revealed that CaH_(2)played a crucial role in promoting the activity of the Ni-carbonate interface for CO_(2)methanation.CaH_(2)could modify the electronic structure of Ni and tune the structural properties of CaCO_(3)to generate medium basic sites (OH groups),which are favorable for the activation of H2and CO_(2).In-situ Fourier transform infrared spectroscopy (FTIR) analysis combined with density functional theory calculations demonstrated that CO_(2)activation occurs at the hydroxyl group (OH) on the CaH_(2)-modified Ni-carbonate surface,leading to the formation of CO_(3)H*species.Furthermore,our study has confirmed that CO_(2)methanation over the Ni/CaH_(2)-CaCO_(3)catalysts proceeds via the formate pathway.

关 键 词：CO_(2)methanation Metal hydride Ni catalysts CARBONATE Metal-carbonate interface 

分 类 号：O643.36[理学—物理化学] X701[理学—化学]