Boosting the catalytic oxidation of ethane over Ce-doped Ru/Co3O4: cooperation of electron-rich Ru and oxygen vacancies

Abstract

Ethane has become one of the most challenging target pollutants in the field of catalytic elimination of volatile organic compounds (VOCs) due to its strong C–H bond (ΔE_C–H = 442 kJ mol⁻¹). Ru/Co₃O₄ is one of the most promising catalysts for ethane oxidation, but its poor low-temperature activity and stability have limited its further application. In this work, the designed Ru/0.1Ce–Co₃O₄ with Ce modification exhibits outstanding catalytic activity. It achieves 90% ethane conversion at 260 °C, which is 70 °C lower than that of Ru/Co₃O₄. Furthermore, it also demonstrates excellent long-term stability, water resistance, and high-temperature resistance. The characterization results confirmed that Ce was successfully doped into the Co₃O₄ lattice, which weakens the Co–O bond strength and increases the oxygen vacancy concentration, consequently facilitating the adsorption and activation of molecular oxygen. Moreover, electron-enriched Ru was observed due to the electron transfer from Ce to Ru, promoting the cleavage of C–H bonds in ethane. The synergistic effect of oxygen vacancies and electron-rich Ru significantly enhances the catalytic activity for ethane oxidation. Notably, the monolithic catalyst obtained by simply coating the Ru/0.1Ce–Co₃O₄ sample powder onto a cordierite support exhibits low-temperature activity and long-term stability in the catalytic oxidation of ethane. This study provides empirical value for designing catalysts for ethane oxidation with practical application potential.