First-Principles Study of NO[sub x] and SO[sub 2] Adsorption onto SnO[sub 2](110)

An ab initio study of the adsorption of and onto surfaces is presented and related to gas-sensing applications. Using first-principles calculations density functional theory–generalized gradient approximation (DFT-GGA), the most relevant and adsorptions were analyzed by estimating their adsorption energies. The resulting values were compared to experimental desorption temperatures for and . The adsorption of the poisoning agent was also analyzed. Optimum working temperatures for minimum poisoning in sensing applications are discussed from the perspective of adsorption. In all cases, we observed that the surface reduction state has dramatic consequences on adsorption strength. An ab initio thermodynamics study is presented to analyze the stability of several surface oxygen configurations with respect to the ambient oxygen partial pressure and the temperature of the material.