2. Jozef Stefan Inst, Jamova Cesta 39, SI-1000 Ljubljana, Slovenia
3. Rudjer Boskovic Inst, Div Mat Phys, Bijenicka Cesta 54, Zagreb 10000, Croatia
折叠
Abstract
The methane dry reforming reaction (DRM) converts methane and CO2 into syngas, a mixture of H-2 and CO. When illuminated by 790 mW cm(-2) of white light, the 2Ni/CeO2-x catalyst converts CH4 and CO2 beyond thermodynamic equilibrium, while the energy efficiency reaches 33%. The DRM reaction is sustained in a purely photocatalytic mode without external heating, yielding CH4 and CO2 rates of 0.21 and 0.75 mmol (g(cat).min)(-1), respectively. Theoretical analysis of Ni/CeO2-x optical properties agrees with in-situ UV-Vis DRS results and reveals partly reduced Ce3+ sites crucial for extending the optical absorption of Ni/CeO2-x into the visible light range. Two photocatalytic mechanisms are postulated to occur: the hot charge-carrier driven photocatalytic mechanism and the near-field induced resonant energy transfer, depending on the energy of photons used to stimulate the catalyst. This work identifies sub-stoichiometric Ni/CeO2-x as highly efficient for boosting methane activation by visible light under mild conditions.
NSTL
Elsevier