基于Jahn-Teller效应设计Ag/Mn3O4-MnO异质结催化甲醛重整产氢

he Jahn-Teller effect has received intense interest in the field of catalysis because of its ability to optimize the surface electron state to tune the adsorption behavior of reactants on catalyst. Herein, direct evidence of the strong Jahn-Teller distortion at the Mn3O4-MnO heterointerfaces is reported, which is used to regulate the electronic and lattice structure of Mn3O4-MnO composite support, and effectively enhance the activity of Ag nanoparticles-catalyzed H2 production from formaldehyde. Benefiting from the improved density and properties of adsorption sites in Mn3O4-MnO by stabilization of the Mn3+ at the heterointerface, the lattice distortion affords abundant active sites for reaction intermediates conversion. Therefore, Ag/Mn3O4-MnO exhibits the highest catalytic efficiency for formaldehyde reforming into H2 at room temperature, which is one order of magnitude higher than its counterpart catalysts, such as Ag/Mn3O4, Ag/MnO and Ag/Mn3O4#MnO. Experimental observations and theoretical calculations indicate that the excellent performance can be attributed to the distorted heterointerface, where the AgNPs and the weak Mn-O bond caused by the strong Jahn-Teller effect are responsible for C?H bond cleavage and O-H activation, respectively. The stabilization of the Mn3+ in Ag/Mn3O4-MnO heterojunctions interfaces results in the local electron accumulation and modulated d electron state, facilitating the adsorption of hydrogen-involving intermediates. This work provides new insights into the Jahn-Teller distortion in catalyst engineering to bring further practical benefits to chemical processes involving sustainable energy conversion.