Support effect on the catalytic activity and stability of non-crystal ternary oxides

Abstract

Supported film catalysts based oxides were reported as very performant catalysts, and their interactions with the support can enhance the catalytic performance. Here, we report the effect of quite inactive and active substrates on the catalytic activity and stability of non-crystal Fe-Cu-Co ternary thin film oxides deposited on stainless steel mesh (SSM) and copper mesh (CuM) by pulsed-spray evaporation chemical vapor deposition (PSE-CVD) technique, was investigated for CO oxidation. The Fe-Cu-Co ternary oxides thin film was thoroughly characterized in terms of structure, morphology, chemical composition, ionic state and optical properties. The obtained results showed that the catalytic performance and stability depended on the nature of the interphase between the metal substrate and the deposited thin film ternary oxides. The physicochemical properties disclosed the formation of needle-like shaped morphology, which leads to sufficient contact area for surface oxygenated species of ternary oxides, which provided abundant sites for oxygen evolution. Moreover, metallic species (Fe3+, Co3+, Co2+ and Cu2+) and electrophilic oxygenated species (O22− or O-) were confirmed to co-exist at the surface and offered effectual synergetic effects on oxidation reaction with better reducibility. The open porosity of nano-grains, abundance of surface metallic and reactive oxygen species, thermal and electrical conductivities, high reducibility at low temperature due to low optical bandgap energies played together a crucial role in the catalytic oxidation reaction. The ternary oxides exhibited attractive performance towards the total oxidation of CO with a high gas hourly space velocity of 81,818 mL·g-1·h-1. The light-off curves shifted towards lower temperature, when ternary oxides thin film deposited on CuM and used in the reaction. Therefore, the doping strategy of active substrate (in the absence of any other oxygen promoter and noble metals support) is used to adapt highly active transition-metal ternary oxides at low temperature, which could further be a very promising way to significantly increase the activity of ternary oxides for catalytic applications.