Electrochemical CO 2 Reduction in Acidic Electrolytes: Spectroscopic Evidence for Local pH Gradients
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Engineering topics
Nie, Weixuan
Publications and source records attributed to Nie, Weixuan.
Organic Additive‐derived Films on Cu Electrodes Promote Electrochemical CO 2 Reduction to C 2+ Products Under Strongly Acidic Conditions
Abstract Electrochemical CO 2 reduction (CO 2 R) at low pH is desired for high CO 2 utilization; the competing hydrogen evolution reaction (HER) remains a challenge. High alkali cation concentration at a high operating current density has recently been used to promote electrochemical CO 2 R at low pH. Herein we report an alternative approach to selective CO 2 R (>70 % Faradaic efficiency for C 2+ products, FE C2+ ) at low pH (pH 2; H 3 PO 4 /KH 2 PO 4 ) and low potassium concentration ([K + ]=0.1 M) using organic film‐modified polycrystalline copper (Modified‐Cu). Such an electrode effectively mitigates HER due to attenuated proton transport. Modified‐Cu still achieves high FE C2+ (45 % with Cu foil /55 % with Cu GDE) under 1.0 M H 3 PO 4 (pH≈1) at low [K + ] (0.1 M), even at low operating current, conditions where HER can otherwise dominate.
Nie, Weixuan↗
Organic Additive–derived Films on Cu Electrodes Promote Electrochemical CO 2 Reduction to C 2+ Products Under Strongly Acidic Conditions
Electrochemical CO 2 reduction (CO 2 R) at low pH is desired for high CO 2 utilization; the competing hydrogen evolution reaction (HER) remains a challenge. High alkali cation concentration at a high operating current density has recently been used to promote electrochemical CO 2 R at low pH. Herein we report an alternative approach to selective CO2R (>70 % Faradaic efficiency for C 2+ products, FE C2+ ) at low pH (pH 2; H 3 PO 4 /KH 2 PO 4 ) and low potassium concentration ([K + ]=0.1 M) using organic film-modified polycrystalline copper (Modified-Cu). Furthermore, such an electrode effectively mitigates HER due to attenuated proton transport. Modified-Cu still achieves high FE C2+ (45 % with Cu foil /55 % with Cu GDE) under 1.0 M H 3 PO 4 (pH≈1) at low [K + ] (0.1 M), even at low operating current, conditions where HER can otherwise dominate.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Strategies for breaking molecular scaling relationships for the electrochemical CO 2 reduction reaction
The electrocatalytic CO 2 reduction reaction (CO 2 RR) is a promising strategy for converting CO 2 to fuels and value-added chemicals using renewable energy sources. Molecular electrocatalysts show promise for the selective conversion of CO 2 to single products with catalytic activity that can be tuned through synthetic structure modifications. However, for the CO 2 RR by traditional molecular catalysts, beneficial decreases in overpotentials are usually correlated with detrimental decreases in catalytic activity. This correlation is sometimes referred to as a “molecular scaling relationship”. Overcoming this inverse correlation between activity and effective overpotential remains a challenge when designing new, efficient molecular catalyst systems. Here, in this perspective, we discuss some of the concepts that give rise to the molecular scaling relationships in the CO 2 RR by molecular catalysts. We then provide an overview of some reported strategies from the last decade for breaking these scaling relationships. We end by discussing strategies and progress in our own research designing efficient molecular catalysts with redox-active ligands that show high activity at low effective overpotentials for the CO 2 RR.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Determining the coordination environment and electronic structure of polymer-encapsulated cobalt phthalocyanine under electrocatalytic CO 2 reduction conditions using in situ X-Ray absorption spectroscopy
In situ X-ray absorbance spectroscopy measurements show that encapsulating cobalt phthalocyanine within coordinating polymers leads to axial ligation of Co and results in enhanced rates for electrocatalytic CO 2 reduction.
Liu, Yingshuo↗