| 초록 |
Selective oxidation of methane to oxygenates such as methanol is an ideal approach for utilization of methane but it is still in challenge. For conventional metal-based catalyst, methane is easily over-oxidized on metal surface. We deposited single-atomic precious metal (Rh, Pd, Pt, and Ir) on zirconia support. The single-atomic character was carried out by HAADF-STEM and CO-DRIFTS. The appropriate model structure was constructed by DFT calculation. On the single-atom catalyst, methanol (MeOH) and methyl hydroperoxide (MeOOH) were produced by methane oxidation with hydroperoxide (H2O2) at low temperature (70°C). The 0.3wt% Rh/ZrO2 showed highest productivity. Productivity was related with the oxidation state of Rh and the oxidic Rh was the active site for selective methane activation. The CH4-DRIFTS and DFT calculations showed stable adsorption of CH3 species on single-atomic Rh/ZrO2 surface. |
