Unveiling the kilogram-scale gold single-atom catalysts via ball milling for preferential oxidation of CO in excess hydrogen

Although CeO2-supported Au single atoms (Au1/CeO2) have great potential in preferential oxidation of CO (PROX) reaction, the large-scale synthesis of such single-atom catalysts (SACs) is still greatly challenging. Herein, we develop a dry ball milling method for the mass production of Au1/CeO2 SACs in large quantities (>1 kg). The as-prepared Au1/CeO2 SACs were demonstrated as highly active, selective, and stable catalysts for PROX at 120 °C with 100% CO conversion. The TOFs of Au1/CeO2 SACs for H2 oxidation at 120 °C (<0.01 s−1) were about two orders of magnitude lower than that for CO oxidation. Moreover, the four Au1/CeO2 SACs with different preparation scales showed essentially identical catalyst structure as well as catalytic performance. This approach can also be extended to prepare a family of oxide-supported noble metal SACs, which may pave a facile path for the mass production of oxide-supported SACs to meet industrialization production requirements.