Mesoporous carbon-encapsulated Co single atoms synthesized via NH4Cl-templated ZnCo–ZIF pyrolysis for efficient ammonium perchlorate catalysis

Abstract

Due to the limited accessibility of active sites and mass transfer efficiency, the application of single atom catalysts (SACs) in complex reactions faces challenges. Here, we report a hierarchical mesoporous carbon framework for synthesizing anchored Co single atoms (Co–SA/meso-C) using a dual template strategy. During the high-temperature pyrolysis process, NH₄Cl encapsulated in ZnCo–ZIF can serve as both a mesopore generator and a micropore etchant, producing mesoporous-ZnCo–ZIF with pore sizes of approximately 5–10 nm. After further pyrolysis to leach out the Zn component, the resulting Co–SA/meso-C exhibits high Co loading, mesoporous properties, and efficient mass transfer channels. In the decomposition of ammonium perchlorate (AP), Co–SA/meso-C can reduce the low-temperature decomposition peak temperature of AP by 147.6 °C. The NH₃ oxidation reaction pathway under the action of Co–SA was verified through DFT calculations. This work provides a reference for designing catalysts that require high activity and mass transfer efficiency and expands their applications in the field of high-temperature catalysis.