Silver halide-induced catalyst poisoning of Ag-M bimetallic nanoparticles (biNPs) and their chemical regeneration

Abstract

Catalyst poisoning is a core research topic in the field of heterogeneous catalysis. Despite its importance, however, the catalytic properties of Ag-M bimetallic nanoparticle (biNP) catalysts have not been investigated with regards to the effect of precursor-induced silver halide byproducts. To address this issue, we demonstrated the synthesis of Ag-Pd and Ag-Pt biNPs of controlled and uniform shapes, sizes, and compositions using chlorometallate and Cl-free precursors and investigated their catalytic properties. Importantly, we discovered that the catalytic properties of the biNPs were significantly enhanced upon AgCl removal using ascorbic acid, which could increase their exposed surface area. Moreover, the structures of the biNPs were maintained after AgCl removal using ascorbic acid, which is a significant advantage over AgCl removal using conventional NH3. This study is the first to report AgCl-induced biNP catalyst poisoning caused by the use of chlorometallate precursors and its chemical regeneration, and can be used as a guideline for the controlled synthesis of biNPs of high purity and their efficient applications in catalysis, plasmonics, biomedical detection, and energy conversion. (C) 2021 Elsevier B.V. All rights reserved.