Cu基催化剂上糠醛转化为糠醇结构敏感性的理论研究

The structure-sensitive of Cu catalyst for furfural conversion to furfuryl alcohol:A theoretical study

本研究采用密度泛函理论方法以Cu(111)和Cu(211)表面为代表研究了Cu基催化剂上糠醛加氢转化为糠醇反应的结构敏感性。通过研究糠醛转化为糠醇过程中反应物、中间物种和产物的吸附及可能的反应机理,得出,在Cu(111)和Cu(211)表面上,糠醛C=O基团的碳原子首先加氢(F-CHO+H→F-CH_(2)O),然后氧原子加氢(F-CH_(2)O+H→F-CH_(2)OH),且第二步是整个反应的速率控制步骤。计算结果表明,Cu(211)表面对糠醇的生成具有较好的催化活性,这是由于该表面能够促进H_(2)解离和增强糠醛吸附,进而促进将糠醛转化为糠醇。本工作为通过调节金属催化剂的微观结构来控制生物质分子转化的活性和选择性提供了一种可行的方法。

The structure-sensitive of Cu catalyst for furfural hydrogenation to furfuryl alcohol was explored by employing Cu(111)and Cu(211)model systems.Herein,the adsorption behavior of reactants and intermediates,and the possible reaction mechanism of furfuryl alcohol formation were investigated.For furfuryl alcohol formation,the preferred pathway is F-CHO+2H→F-CH_(2)O+H→F-CH_(2)OH,in which the second H addition is the rate-determining step.Meanwhile,Cu(211)surface exhibits higher activity to furfuryl alcohol formation than that on Cu(111)surface.According to our analysis,the undercoordinated sites on the Cu(211)surface could facilitate H_(2)dissociation and stabilize the adsorbed furfural,thereby promoting the furfural hydrogenation and the furfuryl alcohol formation.This work provides a feasible approach for regulating the catalytic activity and selectivity in furfural conversion.