Highly active low-temperature HCHO oxidation of mesoporous Pt/CeO2 derived from Pt/CeBDC

Abstract

In the present work, mesoporous Pt/CeO₂(MOF) was synthesized from Pt-containing CeBDC by high-temperature treatment for application in low-temperature HCHO oxidation. The catalytic results show that Pt/CeO₂(MOF) possesses enhanced HCHO oxidation performance where its HCHO conversion rate is up to 78% while that of a commercial CeO₂-supported Pt catalyst is only 31% at room temperature. Simultaneously, in a long-term HCHO oxidation experiment, Pt/CeO₂(MOF) can remain catalytically stable. Kinetic studies demonstrate the more likely oxidation of HCHO molecules on Pt/CeO₂(MOF). Structural characterization shows that Pt/CeO₂(MOF) does not have an organic composition, which is elementally identical to that of a commercial CeO₂-supported Pt catalyst. The Pt nanoparticles of Pt/CeO₂(MOF) are mainly dispersed in the mesopores of CeO₂ to significantly increase the number of Pt–O–Ce interfaces. Due to its structural characteristics, the mesoporous Pt/CeO₂(MOF) possesses more reactive oxygen species, including peroxides (O₂²⁻). HCHO-DRIFTS studies demonstrate that the reaction rates of the two steps of HCHO decomposition, i.e. DOM transformation and CO oxidation, dramatically increase on Pt/CeO₂(MOF). Moreover, the formate decomposition step of Pt/CeO₂(MOF) is relatively faster than those of control catalysts. These factors could be responsible for the excellent low-temperature HCHO oxidation performance of the mesoporous Pt/CeO₂(MOF).