Enhanced photocatalytic CO₂ reduction to fuels through bireforming of methane over structured 3D MAX Ti₃AlC₂/TiO₂ heterojunction in a monolith photoreactor

Design and fabrication of three dimensional Ti₃AlC₂ MAX/TiO₂ composite immobilized over monolithic support was obtained through sol-gel approach. With partial oxidation and incorporation of Ti₃AlC₂ essentially promotes light absorption, charge transfer and extends photo-induced charge carrier lifetime. The highest CO yield of 1566 »μmol »g-cat^-1 was obtained over Ti₃AlC₂ MAX/TiO₂, being 6.8 folds higher than pure TiO₂ NPs. Performance of structured composite tested in methane steam reforming (MSR), methane dry reforming (MDR) and methane bi-reforming (MBR) reveals 1.2 and 1.6 folds higher activity in MBR than using MDR and MSR, respectively. Similarly, quantum yield in a monolith photoreactor was 3.5 folds higher than using a fixed-bed system. This divulges that MBR gave proficient oxidation and reduction reactions in electron-rich 3D MAX structure, whereas, monolith photoreactor provides larger photon-energy consumption with improved sorption process to boost production of CO and H₂ with enhanced stability. Thus, this work demonstrated 3D Ti₃AlC₂ MAX/TiO₂ a promising catalyst and monolith photoreactor an efficient photon flux harvesting system for boosting hydrogen rich syngas production.