The novel contribution of non-noble metal catalysts for intensified carbon dioxide hydrogenation: Recent challenges and opportunities

The enormous growth in anthropologic activities (carbon dioxide (CO2) emissions) and continuous depletion of non-renewable sources have contributed to the problem of climate change and ocean acidification. Hence, CO2 capture/utilization has been widely investigated as an alternative, eco-friendly, and sustainable energy approach. Catalytic CO2 hydrogenation has the potential to effectively produce value-added chemicals and alternative fuels, thus, alleviating global CO2 emissions and reducing harmful environmental impacts. This brief review is focusing on the potential contribution of novel heterogeneous catalysts for the synergic CO2 hydrogenation into carbon monoxide, methanol, and dimethyl ether (DME). Comprehensive/detailed discussions have been made on the enhanced catalytic performance of reverse water–gas shift (RWGS)reaction (∼850 °C) with emphasis on the preparation methods, catalytic supports, non-noble metallic catalysts, and synergistic reaction mechanisms. The role of the Cu-based catalytic system has been featured in enhanced reaction thermodynamics, kinetics, and mechanisms of CO2 hydrogenation. The potential applicability of bi-functional catalysts with advanced water sorbents (zeolites 3A) has been investigated for CO2 conversion to DME through the intensified sorption-enhanced process. Overall, the recent advancements in the area of structure–activity relationships in situ with characterization techniques, and combined experimental catalytic measurements exhibit improved CO2 conversion of 80%, CO selectivity of 99%, methanol selectivity of 100%, and DME selectivity of 66%. The future research interest is directed towards the operation of low-cost and highly efficient water sorbents (i.e., zeolite 13X) with methanol/DME synthesis at <250 °C. Furthermore, the synthesis of bifunctional mixtures of active catalytic phase with adsorbent can be investigated in the optimized hybrid reactors with renewable energy resources for improved CO2 hydrogenation.