Effect of support nature on catalytic activity of the bimetallic RuCo nanoparticles for the oxidative removal of 1,2-dichloroethane

Abstract

The nature of porous support (mesoporous Al2O3 and MgO (denoted as meso-Al2O3 and meso-MgO, respectively) and microporous HZSM-5) on catalytic performance of the bimetallic RuCo nanoparticles (NPs) was investigated for the oxidation of 1,2-dichloroethane (1,2-DCE). Redox and acid properties and reaction intermediates of the samples were measured by means of various techniques. The RuO2 species were dominantly present in the supported bimetallic samples, and Co doping could increase the length of the Ru−O bond. Compared with RuCo/meso-MgO and RuCo/meso-Al2O3, RuCo/HZSM-5 exhibited the highest catalytic activity (T90% =281 °C, TOFNoble metal = 3.6 × 10−3 s−1, reaction rate at 270 °C = 18.7 μmol/(gNoble metal s), and apparent activation energy =36 kJ/mol at SV = 20,000 mL/(g h)) and the best Cl-resistant performance, which was associated with its strong redox ability, suitable acidity, good 1,2-DCE adsorption capacity, highly dispersed RuCo NPs, and strong interaction between RuCo NPs and HZSM-5. Loading of RuCo NPs on the support could suppress the formation of C2H3Cl and improve the Cl-resistant performance. Over the RuCo/HZSM-5 sample, the partial deactivation induced by water vapor or HCl addition was reversible, while that induced by SO2 introduction was irreversible. Based on the characterization results, we believe that the oxidation of 1,2-DCE over RuCo/meso-Al2O3, RuCo/meso-MgO or RuCo/HZSM-5 might take place concurrently via the Langmuir−Hinshelwood and Mars−van Krevelen mechanisms. This work can provide a strategy to develop the efficient catalysts with low Cl-containing by-products formation, high CO2 selectivity, and good Cl-resistance in the oxidative removal of Cl-VOCs under the practical conditions.