Progress in research on catalysts for catalytic oxidation of formaldehyde

Abstract

Formaldehyde (HCHO) is carcinogenic and teratogenic, and is therefore a serious danger to human health. It also adversely affects air quality. Catalytic oxidation is an efficient technique for removing HCHO. The development of highly efficient and stable catalysts that can completely convert HCHO at low temperatures, even room temperature, is important. Supported Pt and Pd catalysts can completely convert HCHO at room temperature, but their industrial applications are limited because they are expensive. The catalytic activities in HCHO oxidation of transition-metal oxide catalysts such as manganese and cobalt oxides with unusual morphologies are better than those of traditional MnO2, Co3O4, or other metal oxides. This is attributed to their specific structures, high specific surface areas, and other factors such as active phase, reducibility, and amount of surface active oxygens. Such catalysts with various morphologies have great potential and can also be used as catalyst supports. The loading of relatively cheap Ag or Au on transition-metal oxides with special morphologies potentially improves the catalytic activity in HCHO removal at room temperature. The preparation and development of new nanocatalysts with various morphologies and structures is important for HCHO removal. In this paper, research progress on precious-metal and transition-metal oxide catalyst systems for HCHO oxidation is reviewed; topics such as oxidation properties, structure–activity relationships, and factors influencing the catalytic activity and reaction mechanism are discussed. Future prospects and directions for the development of such catalysts are also covered.