Positively charged silver improve carbon dioxide electroreduction reaction performance by introducing phosphate

For noble metal catalysts such as Au and Ag, the weak adsorption of intermediates is an important factor in limiting the efficiency of CO2 electroreduction. Positively charged metals, which can lower the energy barriers of intermediate reactions, greatly facilitate the rapid conversion of CO2 molecules. In this work, a simple in situ synthesis method was utilized to form an Ag3PO4 oxide layer on the surface of Ag foil, and the oxidation state of silver retained after pre-reduction. The Ag3PO4/Ag catalyst not only increased the electrochemical surface area, but also enhanced the adsorption of intermediates to the active sites, resulting in the catalytic selectivity of 94.4% for the electroreduction of CO2 to CO. DFT calculations show that through internal electron regulation, PO43- can stabilize the positive state of Ag, thus increasing the Ag-O bond energy, which is conducive to the reduction of the reaction energy barrier and the improvement of catalytic stability.