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The extensive utilization of fossil fuels has led to a rapid increase in atmospheric CO2 concentration, resulting in various environmental issues. To reduce reliance on fossil fuels and mitigate CO2 emissions, it is important to explore alternative methods of utilizing CO2 and H2 as raw materials to obtain high-value-added chemicals or fuels. One such method is CO2 methanation, which converts CO2 and H2 into methane (CH4), a valuable fuel and raw material for other chemicals. However, CO2 methanation faces challenges in terms of kinetics and thermodynamics. The reaction rate, CO2 conversion, and CH4 yield need to be improved to make the process more efficient. To overcome these challenges, the development of suitable catalysts is essential. Non-noble metal catalysts have gained significant attention due to their high catalytic activity and relatively low cost. In this paper, the thermodynamics and kinetics of the CO2 methanation reaction are discussed. The focus is primarily on reviewing Ni-based, Co-based, and other commonly used catalysts such as Fe-based. The effects of catalyst supports, preparation methods, and promoters on the catalytic performance of the methanation reaction are highlighted. Additionally, the paper summarizes the impact of reaction conditions such as temperature, pressure, space velocity, and H2/CO2 ratio on the catalyst performance. The mechanism of CO2 methanation is also summarized to provide a comprehensive understanding of the process. The objective of this paper is to deepen the understanding of non-noble metal catalysts in CO2 methanation reactions and provide insights for improving catalyst performance. By addressing the limitations of CO2 methanation and exploring the factors influencing catalyst effectiveness, researchers can develop more efficient and cost-effective catalysts for this reaction. [ABSTRACT FROM AUTHOR]

The excessive consumption of fossil fuels has resulted in massive carbon emissions and serious ecological and environmental crises. Therefore, achieving the efficient utilization of waste carbon sources is considered as an important pathway to addressing the aforementioned issues in the context of carbon neutrality. Developing and designing suitable catalyst materials has become the key to converting COx into valuable platform chemicals and value-added liquid fuels (e.g., CO, CH4, CH3OH, and C2+ hydrocarbons). A moderate interaction between nitrogen-doped carbon materials and active metals is more favorable for the progress of the COx hydrogenation reaction compared to traditional metal oxide carriers. In this work, we comprehensively summarize the synthesis methods of N-doped carbon materials and the relevant research progress in the field of COx hydrogenation. In addition, a general assessment of carbon-based catalysts for COx hydrogenation reactions, concerning the support and metal properties, the activity and product selectivity, and their interactions is systematically discussed. Finally, this review discusses the roles of N-doped carbon materials, the current challenges, and future development directions. [ABSTRACT FROM AUTHOR]

The malignant environmental changes caused by the ever-increasing amount of anthropogenic CO2 emissions have been particularly prominent in recent years. To achieve carbon mitigation and carbon neutrality, CO2 hydrogenation to methanol is regarded as a promising and sustainable route. However, the development of catalysts with exceptional performance and the establishment of a clear structure–activity relationship remain formidable challenges. Considering the lack of a state-of-the-art review on the catalytic progress of CO2 hydrogenation to methanol over non-noble catalysts, we conducted a detailed review in terms of the thermodynamic analysis, catalytic development, and reaction mechanism. In this work, we mainly reviewed the latest research progress of different catalysts including Cu-based, In2O3-based, bimetallic, solid solution, and other catalysts. Meanwhile, we summarized the effects of the support materials, promoters, and preparation methods on the catalytic performance. In addition, we also summarized the possible reaction mechanisms of direct hydrogenation of CO2 to methanol. Overall, this work would be of importance for the researchers to obtain a comprehensive understanding of the design and development of efficient catalysts for CO2 hydrogenation to methanol. [ABSTRACT FROM AUTHOR]

As the global climate crisis escalates, reductions in CO2 emissions and the efficient utilization of carbon waste resources have become a crucial consensus. Among the various carbon mitigation technologies, the concept of power-to-liquid (PTL) has gained significant attention in recent years. Considering the lack of a timely review of the state-of-the-art progress of this PTL process, this work aims to provide a systematic summary of the advanced PTL progress. In a CO2 capture unit, we compared the process performances of chemical absorption, physical absorption, pressure swing adsorption, and membrane separation technologies. In a water electrolysis unit, the research progress of alkaline water electrolysis, proton exchange membrane water electrolysis, and solid oxide water electrolysis technologies was summarized, and the strategies for improving the electrolysis efficiency were proposed. In a CO2 hydrogenation unit, we compared the differences of high-temperature and low-temperature Fischer–Tropsch synthesis processes, and summarized the advanced technologies for promoting the conversion of CO2 into high value-added hydrocarbons and achieving the efficient utilization of C1–C4 hydrocarbons. In addition, we critically reviewed the technical and economic performances of the PTL process. By shedding light on the current state of research and identifying its crucial factors, this work is conducive to enhancing the understanding of the PTL process and providing reliable suggestions for its future industrial application. By offering valuable insights into the PTL process, this work also contributes to paving the way for the development of more efficient and sustainable solutions to address the pressing challenges of CO2 emissions and climate change. [ABSTRACT FROM AUTHOR]