氧化亚钴表面CO活化解离反应机理的DFT计算

DFT Calculation Study on CO Activation and Dissociation Mechanism on Cobalt Oxide

本文使用密度泛函理论计算在原子尺度上研究了氧化亚钴表面合成气(H_(2)+CO)的吸附情况以及CO的H辅助活化解离过程。对氧化亚钴的表面几何结构及其表面CO活化的可能反应机理进行了系统研究。吸附计算结果表明相比于CoO的三个晶面,金属Co(10-11)有着对CO、H和表面CH_(x)物种更强的吸附;反应机理的计算结果表明当CO吸附在CoO(200)表面后可以通过H辅助路径进行活化解离,微观动力学结果揭示了CO解离过程中表面物种的覆盖度。本文为进一步研究钴基费托合成催化剂的催化性能提供了理论依据。

In this study,density functional theory calculations are used to study the adsorption of syngas and the H-assisted CO dissociation process on cobalt oxide at the atomic scale.The surface geometry of the cobalt oxide and the possible reaction mechanism of CO activation on the surface were systematically studied.The adsorption results shows that,in comparison with CoO,the metallic Co has a stronger adsorption ability for CO,H,and CH_(x) species.The reaction mechanism results show that when CO is adsorbed on the CoO(200)surface,CO activation follows the H-assisted reaction pathway.The microkinetics results reveal the coverage of surface species in CO dissociation process.This work provides a theoretical insights for further research on the catalytic performance of cobalt-based catalysts.