Al2O3 BiF3 nanostructure CH4 CO2 CO2 feedstock CO2 reforming CeO2 Chemical engineering H-ZSM-5 La2O3 MgO NOx mitigation (deNOx) POP composite Power-to-Gas Rz ink Technology: general issues TiO2 nanorods W and V catalytic sites ZnO nanorods ZrO2 carbon deposition carbon dioxide (CO2) carbon monoxide (CO) catalysis catalyst catalyst design ceramic foams cerium dry reforming environmental nanocatalysis