Theoretical analysis of methanol and hydrogen adsorptions on SnO2 by molecular orbital calculation

Adsorptions of methanol and hydrogen molecules on (100) and (001) SnO2 surfaces have been investigated by using molecular orbital (MO) calculation, and compared with experimental data of gas sensing. From MO calculation, adsorption of methanol molecule on SnO2 surface tends to occur compared with H2 molecule adsorption, in contrast to experimental data. Moreover, methanol can react with adsorbed O2 molecule on SnO2 surface. So, it is considered that the sensitivity of SnO2 gas sensor is induced by adsorption of hydrogen atom or CH3 species rather than that of hydrogen or methanol molecule.