Pt-Anchored CuCrO₂ for Low-Temperature-Operating High-Performance H₂S Chemiresistors

Recent advances in heterogeneous catalysts indicate that single atoms (SAs), anchored/stabilized on metal oxide nanostructures, exhibit not only high catalyst atom efficiency but also intriguing reactivity and selectivity. Herein, isolated Pt SA-anchored CuCrO₂ (CCO) has been designed by a glycine-nitrate solution combustion synthesis (SCS) route. The density of isolated Pt SAs achieves the highest value of ∼100 μm^-2 for the 1.39 wt % Pt-anchored CCO sample, which results in the drastically boosted H₂S response characteristics, including a high response of 1250 (35 times higher than that of pure CCO) at 10 ppm H₂S and a low operating temperature of 100 °C. Except for CH₄S, the responses of a 1.39 wt % Pt-anchored CCO chemiresistor to diverse vapors with concentrations of 50-100 ppm are less than 2, exhibiting excellent selectivity. Various ex situ characterizations indicate that the spillover catalytic effect of Pt SA sites, other than the conventional sulfuration-desulfuration mechanism, plays a dominant role in the outstanding H₂S response characteristics.