Research Progress in Conversion of CO2 to Valuable Fuels

Abstract

Rapid growth in the world’s economy depends on a significant increase in energy consumption. As is known, most of the present energy supply comes from coal, oil, and natural gas. The overreliance on fossil energy brings serious environmental problems in addition to the scarcity of energy. One of the most concerning environmental problems is the large contribution to global warming because of the massive discharge of CO2 in the burning of fossil fuels. Therefore, many efforts have been made to resolve such issues. Among them, the preparation of valuable fuels or chemicals from greenhouse gas (CO2) has attracted great attention because it has made a promising step toward simultaneously resolving the environment and energy problems. This article reviews the current progress in CO2 conversion via different strategies, including thermal catalysis, electrocatalysis, photocatalysis, and photoelectrocatalysis. Inspired by natural photosynthesis, light-capturing agents including macrocycles with conjugated structures similar to chlorophyll have attracted increasing attention. Using such macrocycles as photosensitizers, photocatalysis, photoelectrocatalysis, or coupling with enzymatic reactions were conducted to fulfill the conversion of CO2 with high efficiency and specificity. Recent progress in enzyme coupled to photocatalysis and enzyme coupled to photoelectrocatalysis were specially reviewed in this review. Additionally, the characteristics, advantages, and disadvantages of different conversion methods were also presented. We wish to provide certain constructive ideas for new investigators and deep insights into the research of CO2 conversion.

A Combined Chemical-Electrochemical Process to Capture CO2 and Produce Hydrogen and Electricity

“…Therefore, agitation should be provided. The diffusion limited fluxes were calculated using Equation (11). The value of the SDL thickness (d) is inversely proportional to the amount of agitation; therefore, increased agitation will decrease the d value and increase the limiting ionic flux.…”

“…Several authors have carried out research projects on the chemical conversion of CO 2 into high-value-added carbon compounds, such as methanol, organic materials, and plastic materials ( [7][8][9][10][11][12][13], among others). However, due to low conversion efficiency, it has been argued that it cannot be an effective greenhouse gas sequestration technology [14,15].…”

para-Aminobenzoic acid-capped hematite as an efficient nanocatalyst for solvent-free CO2 fixation under atmospheric pressure

“…2 To restrain the accumulation of excess CO 2 in the atmosphere, different strategies have been employed like CO 2 capture and storage, CO 2 fixation into value-added chemicals, development of zero-carbon emission fuels, and more. [3][4][5][6][7] Among them, the utilization of CO 2 as C1 feedstock is advantageous as CO 2 is abundant, renewable and nontoxic. To date, many chemicals and fuels have been successfully synthesized employing CO 2 through both reductive and non-reductive methods.…”

“…To date, many chemicals and fuels have been successfully synthesized employing CO 2 through both reductive and non-reductive methods. 7,8 Some of the most commercialized CO 2 derived chemicals are urea, salicylic acid, cyclic carbonates, polyols, methanol and methane. 9 In particular, cyclic carbonates are interesting due to their unique properties such as significant polarity and high boiling point enabling great industrial importance.…”

Biocatalytic Reduction of Formaldehyde to Methanol: Effect of pH on Enzyme Immobilization and Reactive Membrane Performance

“…The aim of the framework calls for limiting global warming to a rise of 1.5-2 °C [6]. Thus, critical measures must be made to reduce atmospheric CO2 levels, such as carbon capture and storage [7][8][9], direct emission reduction of CO2 by development of clean and sustainable energy resources replacing nonrenewable fossil fuels and converting CO2 into useful chemicals [10,11].…”