Molecular sieve confined catalysts for the catalytic combustion of VOCs: preparation, application and future development

Abstract

Escalating air quality concerns due to rapid industrialization and urbanization have highlighted the significant environmental and health impacts of volatile organic compounds (VOCs). Among various abatement technologies, catalytic combustion is an efficient method to eliminate VOCs. This review examines the latest progress and impending challenges associated with molecular sieve-confined catalysts in the context of VOCs catalytic combustion. We begin by discussing the pressing need to address air quality issues caused by VOCs emissions. We then delve into the limitations of existing VOCs management approaches and highlight the potential of catalytic oxidation technologies, particularly those utilizing non-precious metal catalysts. The review centers on the effectiveness of molecular sieve-confined catalysts, exploring their unique structure-property relationships and their impact on VOCs elimination. We have summarized the general properties and compositional designs of molecular sieve-confined metal catalysts with active metal species of three distinct sizes: single atoms, nanoclusters, and nanoparticles. Additionally, we have introduced the significant impact of three key aspects of support property regulation on molecular sieve-confined catalysts: the regulation of the molecular sieve carrier framework structure, pore size, and type of framework cations. To gain insights into the fundamental reaction mechanisms, we discuss the kinetic models commonly employed in VOCs catalytic oxidation reactions. We then delve into the reaction mechanisms and structure-activity relationships of VOCs catalytic combustion catalysts, examining factors influencing catalyst activity, stability, and hydrothermal stability. Lastly, we address the practical challenges and future prospects of using molecular sieve-confined catalysts in VOCs catalytic combustion, emphasizing the need for further research in detailed mechanism exploration, development of efficient confined catalysts, and synergistic degradation of multi-component VOCs.