Navigating the catalytic landscape for methyl ethyl ketone abatement: A critical review of noble metal versus metal oxide strategies.

Abstract

Methyl ethyl ketone (MEK) is a prevalent oxygenated volatile organic compound (VOC) whose complex oxidation behavior makes it an important model molecule for catalysis studies. Its abatement is complicated by competing C-C bond scission versus dehydrogenation pathways, the prevalence of which is highly dependent on catalyst design. This is the first comprehensive review dedicated specifically to MEK thermocatalytic abatement, focusing on catalyst development, reaction mechanisms, and performance metrics. Its single-molecule focus enables a deeper mechanistic analysis than is possible in broader VOC surveys, clarifying structure-performance relationships. We critically examine supported noble metal catalysts (SNMCs) and transition metal oxides (TMOs), covering the roles of supports, promoters (e.g., manganese oxide (MnO_x) and cerium dioxide (CeO₂)), and nanostructure. While SNMCs offer high activity at low temperatures, TMOs like perovskites and MnO_x emerge as cost-efficient alternatives. The review contrasts how catalyst properties dictate pathway selectivity. Practical challenges from co-contaminants (e.g., water, sulfur, and chlorine) and strategies to enhance stability are discussed. A comparative performance analysis underscores that catalyst selection depends on the desired optimization metric. The review concludes by identifying critical research gaps, emphasizing the need for standardized protocols and long-term stability studies to bridge laboratory and industrial applications.