Improving the Cu/ZnO-Based Catalysts for Carbon Dioxide Hydrogenation to Methanol, and the Use of Methanol As a Renewable Energy Storage Media

Abstract

Heterogeneous catalytic hydrogenation of carbon dioxide (CO2) to methanol is a practical approach to mitigating its greenhouse effect in the environment while generating good economic profits. Though applicable on the industrial scale through the syngas route, the catalyst of Cu/ZnO/Al2O3 suffers from a series of technical problems when converting CO2 to methanol directly, which include low single-pass conversion, low methanol selectivity, requiring high pressure and fast deactivation by the reverse water gas shift reaction. Over the years, intensive research efforts have been devoted to proffering solutions to these problems by modifying the existing catalyst or developing new active catalysts. However, the open question is if this type of widely used industrial catalyst still promising for CO2 methanolizing reaction or not? This paper reviews the history of the methanol production in industry, the impact of CO2 emission on the environment, and analyzes the possibility of the Cu/ZnO-based catalysts for the direct hydrogenation of CO2 to methanol. We not only address the theoretical and technical aspects but also provide insightful views on catalyst development.

Century of Technology Trends in Methanol Synthesis: Any Need for Kinetics Refitting?

“…13 The catalyst activity is still under investigation, and recent publications demonstrate that there exists the potential for improving the catalyst formulation also in the perspective of CO 2 hydrogenation to methanol. 14,15 Deepening the analysis of new technologies and apparatus (Figure 5), it is worth noting that most of the innovations in the last three decades deal with feedstock. This is mainly due to the change of raw materials used in syngas production, first from fossil to renewable sources and, then, to CO 2 for direct conversion.…”

Impacts of the Catalyst Structures on CO2 Activation on Catalyst Surfaces

“…Yu et al [96] demonstrated through spin-polarized DFT calculations that adsorption and dissociation of CO 2 was dependent on the Co particle size. They showed that Co 55 nanoclusters had the highest CO 2 dissociation activity in comparison to Cu-based materials have gained much attention in the CO 2 conversion process due to their wide applicability in the different conversion processes and low cost [12,97]. Despite these and other massive studies, the activation of CO 2 on Cu catalysts is still an issue due to the poor understanding of its mechanism.…”

CO2 Activation and Hydrogenation on Cu-ZnO/Al2O3 Nanorod Catalysts: An In Situ FTIR Study

“…Different types of catalysts have been investigated for the thermocatalytic hydrogenation of CO 2 to methanol, including supported metal [ 8 , 9 ] and metal oxide [ 10 , 11 ] catalysts. Cu-based catalysts have been reported to have the best activity for methanol production under industrially relevant conditions (5–10 MPa and 200–300 °C) [ 12 , 13 ]. The Cu-ZnO-Al 2 O 3 catalyst prepared via the co-precipitation method is the industrial catalyst used for methanol production from CO + H 2 ; thus, the Cu-ZnO-based catalysts are widely investigated for CO 2 hydrogenation to methanol as well [ 14 , 15 ].…”