Advances in Clean Fuel Ethanol Production from Electro-, Photo- and Photoelectro-Catalytic CO2 Reduction

Abstract

Using renewable energy to convert CO2 to a clean fuel ethanol can not only reduce carbon emission through the utilization of CO2 as feedstock, but also store renewable energy as the widely used chemical and high-energy-density fuel, being considered as a perfect strategy to address current environment and energy issues. Developing efficient electrocatalysts, photocatalysts, and photoelectrocatalysts for CO2 reduction is the most crucial keystone for achieving this goal. Considerable progresses in CO2-based ethanol production have been made over the past decades. This review provides the general principles and summarizes the latest advancements in electrocatalytic, photocatalytic and photoelectrocatalytic CO2 conversion to ethanol. Furthermore, the main challenges and proposed future prospects are illustrated for further developments in clean fuel ethanol production.

Hydrogen Production via Pd-TiO2 Photocatalytic Water Splitting under Near-UV and Visible Light: Analysis of the Reaction Mechanism

“…Thus, the following reaction mechanism towards ethanol photoregeneration can be postulated as [20]: 2 CO…”

Photoelectrochemical CO2 Reduction Products Over Sandwiched Hybrid Ga2O3:ZnO/Indium/ZnO Nanorods

“…On the basis of the CO 2 reduction of major products, the simplified CO 2 reduction mechanism is depicted in Figure 8 ( Sohn et al, 2017 ; Wang et al, 2019 ; Song et al, 2020 ; Prabhu et al, 2020 ; Sun et al, 2021 ; da Silva Freitas et al, 2021 ; Ješić et al, 2021 ; Ochedi et al, 2021 ; Chen et al, 2021 ; Bellardita et al, 2021 ). In an NaHCO 3 electrolyte saturated with CO 2 , two processes are initially involved; H + + e − → H ad and CO 2 + H + + e − → HOOC ad .…”

“…In an NaHCO 3 electrolyte saturated with CO 2 , two processes are initially involved; H + + e − → H ad and CO 2 + H + + e − → HOOC ad . The surface H ad is liberated as gaseous H 2 via H ad + H + + e − → H 2 or H ad + H ad → H 2 ( Sohn et al, 2017 ; Wang et al, 2019 ; Prabhu et al, 2020 ; Song et al, 2020 ; Bellardita et al, 2021 ; Chen et al, 2021 ; da Silva Freitas et al, 2021 ; Ješić et al, 2021 ; Ochedi et al, 2021 ; Sun et al, 2021 ). This process became pronounced when the thickness of GZO was increased.…”

“…Producing recycled energy products using abundant CO 2 is another challenging project for future solutions for energy and environment ( Sohn et al, 2017 ; Wang et al, 2019 ; Prabhu et al, 2020 ; Song et al, 2020 ; Bellardita et al, 2021 ; Chen et al, 2021 ; da Silva Freitas et al, 2021 ; Ješić et al, 2021 ; Ochedi et al, 2021 ; Sun et al, 2021 ). Electrochemical CO 2 reduction is a promising method, and the development of electrodes is a major goal for approaching practical application in the industry.…”

Electrochemical Reduction of Carbon Dioxide to Ethanol: A Review

“…(3) photochemical; (4) biochemical; (5) chemo-enzymatic; and (6) other approaches such as esterification, methanation, dry reforming, hydrogenation, and so on. Due to chemical inertness and high stability of CO 2 , [9,10] the traditional CO 2 absorption, activation, and catalytic conversion processes have some drawbacks, [8] such as high energy requirement for conversion, slow conversion rate to produce different chemicals, catalyst deactivation, etc. The conversion of CO 2 by electrochemical reduction technique has received much interest due to unique advantages, as given in Table 1.…”