Recent Advances in Carbon Dioxide Hydrogenation to Methanol via Heterogeneous Catalysis

Abstract

The utilization of fossil fuels has enabled an unprecedented era of prosperity and advancement of well-being for human society. However, the associated increase in anthropogenic carbon dioxide (CO2) emissions can negatively affect global temperatures and ocean acidity. Moreover, fossil fuels are a limited resource and their depletion will ultimately force one to seek alternative carbon sources to maintain a sustainable economy. Converting CO2 into value-added chemicals and fuels, using renewable energy, is one of the promising approaches in this regard. Major advances in energy-efficient CO2 conversion can potentially alleviate CO2 emissions, reduce the dependence on nonrenewable resources, and minimize the environmental impacts from the portions of fossil fuels displaced. Methanol (CH3OH) is an important chemical feedstock and can be used as a fuel for internal combustion engines and fuel cells, as well as a platform molecule for the production of chemicals and fuels. As one of the promising approaches, thermocatalytic CO2 hydrogenation to CH3OH via heterogeneous catalysis has attracted great attention in the past decades. Major progress has been made in the development of various catalysts including metals, metal oxides, and intermetallic compounds. In addition, efforts are also put forth to define catalyst structures in nanoscale by taking advantage of nanostructured materials, which enables the tuning of the catalyst composition and modulation of surface structures and potentially endows more promising catalytic performance in comparison to the bulk materials prepared by traditional methods. Despite these achievements, significant challenges still exist in developing robust catalysts with good catalytic performance and long-term stability. In this review, we will provide a comprehensive overview of the recent advances in this area, especially focusing on structure–activity relationship, as well as the importance of combining catalytic measurements, in situ characterization, and theoretical studies in understanding reaction mechanisms and identifying key descriptors for designing improved catalysts.

Novel Heterogeneous Catalysts for CO2 Hydrogenation to Liquid Fuels

“…Therefore, we mainly introduce the work of highly selective conversion of CO 2 to CH 3 OH, as there have been many excellent recent reviews on methanol synthesis via heterogeneous catalysis. 12 , 23 − 27 …”

Electrocatalysts for direct methanol fuel cells to demonstrate China's renewable energy renewable portfolio standards within the framework of the 13th five-year plan

“…To illustrate the difference between reverse water gas shift reaction [ 168 ] and methanol synthesis, the most common reaction conditions are summarized in Table 3c (for reverse water gas shift reaction) and 3D (methanol synthesis) ( Table 3d ).…”

Research Progress in Conversion of CO2 to Valuable Fuels

“…There are still great challenges in developing catalysts with high catalytic performance and long-term stability, reducing the size of thermal catalytic reactors and decreasing the production costs. In addition, more effective and economical methods to produce H 2 are urgently needed [ 13 ]. In this case, CO 2 conversion to useful fuels are attempted by other methods such as photocatalysis, electrocatalysis, and photoelectrocatalysis.…”

“…To complete such a reaction, high temperature, high pressure environment, or highly efficient catalysts are typically required to provide the necessary energy. Till now, different strategies including thermal catalysis [ 9 , 10 , 11 , 12 , 13 ], photocatalysis [ 14 , 15 , 16 , 17 ], electrocatalysis [ 18 , 19 , 20 , 21 ], and photoelectrochemical (PEC) reactions [ 22 , 23 , 24 , 25 ] have been adopted to conduct the reduction of CO 2 , in which heat, light, or electricity were used to supply essential energy for the reaction. As is known, eight electrons are needed for each CO 2 molecule to complete the conversion to hydrocarbon compounds.…”