Insights into catalytic valorization of industrial high-concentration nitrous oxide for propylene synthesis

Abstract

Industrial nitrous oxide (N2O) emissions with high concentrations pose a significant challenge to climate change, while the oxidative dehydrogenation of propane (ODHP) with N2O presents a promising strategy for N2O valorization. However, the activity-selectivity trade-off and rapid deactivation by coke deposition remain challenges for future applications. Here, we select Pd/TiO2 as model catalysts and design spatially separated redox centers on the rutile phase catalyst (Pd/R-TiO2), which enable parallel adsorption and independent activation of C3H8 on metallic Pd sites and N2O on oxygen vacancies. Besides, it suppresses product overoxidation by reducing reactive oxygen species concentration near C3 intermediates, enhancing C3H6 selectivity while inhibiting enolic intermediate and coke formation to ensure catalyst stability. Hydrogen spillover from Pd sites to TiO2 surface connects the separated redox reactions, completing the catalytic cycle. This work presents a rational strategy for catalyst design in N2O-ODHP, contributing to the sustainable mitigation of non-CO2 greenhouse gases.