Electrode Build‐Up of Reducible Metal Composites toward Achievable Electrochemical Conversion of Carbon Dioxide

Abstract

At the beginning of the 21st century, our world is faced with a global-warming problem due to the continuous increase in carbon dioxide emission, and thus, the development of novel experimental techniques is needed. The electrochemical conversion of carbon dioxide into high-value organic compounds could be of vital importance to solve this issue. The biggest challenge has always been to develop an electrocatalyst that is chemically active and structurally stable. Herein, previous studies, recent approaches, and current points of view on the electrode structure of metal oxide composites for the advanced electrochemical conversion of carbon dioxide are reviewed.

Looking Back and Looking Ahead in Electrochemical Reduction of CO2

“…Looking ahead, several challenges still remain for realization of the practical use of CO 2 reduction: (1) the CO 2 electrochemistry ( e. g ., mechanism, rate determining step and intermediates) needs to be more clearly identified, which can lead to tuning the reaction selectivity specifically toward the desired products; (2) Even though a couple of state of the art experimental and computational techniques have been implemented, the most active site or phase is under debate. Using scanning electrochemical cell microscopy (SECCM), a direct evidence was provided for the relationship between CO 2 reduction activity and grain boundaries that promote dislocation density of polycrystalline materials, whereas the question of whether oxidized metal species and/or oxygen partially remaining in surface and subsurface regions is directly involved in CO 2 electroreduction remains unclear . In this respect, in‐situ and operando characterization is essential for further understanding of the nature of catalytic surface and rational design of catalyst; (3) Recently, a reactor design of maximizing reaction interface at a catalyst in highly alkaline media (10 M KOH) was proposed, which achieves faradaic efficiency of 70 % for C 2 H 4 at −0.55 V ( vs .…”

“…Fundamental aspects of ECRP started to be studied in the 19 th century and tremendous works have been recently promoted since early works by Hori and co‐workers . Several review papers have already summarized historical and recent remarkable studies on the field . Only a few representative studies are presented here with current research progress at the Ertl center and other groups in South Korea.…”

“…Sn‐based materials are well known as the best catalysts that can catalyze electrochemical reduction of CO 2 to HCOO − . The oxidized Sn species (SnO x ) have been focused to facilitate selective production of HCOO − during ECRP …”

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…[1,2] At present, the major sourceso fe nergy are fossil fuels (coal, petroleum, and natural gas), which are nonrenewable within as hort time period.A tt he presente nergy consumption rate, the estimated fuel reserves will last only 50-100 years. [4,5] Recently,much researchattention has been paid to developing new forms of clean energy,s uch as tidal energy,o cean thermal energy,w ind energy,a nd solar energy. Furthermore, the major disadvantage of burningf ossil fuels is the emission of CO 2 along with SO 2 and different nitrogen oxides.…”

Liquid Hydrocarbon Production from CO2: Recent Development in Metal‐Based Electrocatalysis

“…[60,61] Given such widespreadinterest, it is thus imperative to have acomprehensive overview of the various electrocatalysts developed for the electrochemical and photo-assisted electrochemical reduction of CO 2 into liquid products to identify the trends, gaps in research, and challenges that are hindering the commercialization of this technology to tackle global warming, at least to a certain extent. Currentr eviewso nC O 2 reduction have summarized the catalytic performance obtained with different classes of catalysts, [62][63][64] nanostructures, [65][66][67] composites, [68] reaction pathways, [69] interaction of the electrolyte with CO 2 , [70] metal complexes, [71] and categorizing the different catalysts based on the generated products. [29,72,73] Likewise, valuable lessons can also be gained from the product-specific reviews on electrochemical conversion of CO 2 into HCOO À [74,75] and CH 3 OH.…”