Universal Synthesis of Single-Atom Catalysts by Direct Thermal Decomposition of Molten Salts for Boosting Acidic Water Splitting.

Single-atom catalysts (SACs) are considered prominent materials in the field of catalysis due to their high metal atom utilization and selectivity. However, the wide-ranging applications of SACs remain a significant challenge due to their complex preparation processes. Here, we report a universal strategy to prepare a series of noble metal single atoms on different non-noble metal oxides through a facile one-step thermal decomposition of molten salts. By using a mixture of non-noble metal nitrate and a small-amount noble metal chloride as the precursor, noble metal single atoms can be easily introduced into the non-noble metal oxide lattice owing to the cation-exchange in the in-situ formed molten salt, followed by the thermal decomposition of nitrate anions during the heating process. Analyses using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and extended X-ray absorption fine structure spectroscopy confirm the formation of the finely dispersed single atoms. Specially, the as-synthesized Ir single atoms (10.97 wt%) and Pt single atoms (4.60 wt%) on the Co 3 O 4 support demonstrate outstanding electrocatalytic activities for oxygen evolution reaction and hydrogen evolution reaction, respectively. This article is protected by copyright. All rights reserved.