Reusable Plasma‐Sprayed Transition Metal Oxide Catalyst for Catalytic Wet Oxidation of Organic Waste

Abstract Catalytic wet oxidation (CWO) is an efficient and environmentally friendly method for decomposing organic wastes. This work uses transition metal oxide powders of FeO, MnO 2 , NiO and the novel mixed oxide Co 1.5 Mn 1.5 O 4 , for plasma‐spraying on stainless‐steel substrates to prepare catalyst plates. These catalysts were used to treat d‐glucose as a model compound for organic waste, using CWO process reactions at temperatures from 150 °C to 170 °C and in the presence of oxygen (20 bar and 40 bar). The catalysts were pre‐oxidised to their suitable phases for better catalytic activity. The plasma‐sprayed Fe 2 O 3 catalysts showed the highest chemical oxygen demand (COD) reduction of 72 %. At high reaction severity the catalyst performances were similar improving the overall performance compared to non‐catalytic wet oxidation reactions. Plasma‐sprayed Fe 2 O 3 was found to be the best catalyst for future CWO trials due to its ability to withstand the reaction severity and acetic acid production.