Cu/Bi metal-organic framework-based systems for an enhanced electrochemical transformation of CO2 to alcohols

Sustainable Membrane‐Coated Electrodes for CO2 Electroreduction to Methanol in Alkaline Media

“…The decreasing FE to methanol with increasing potential and current density at higher overpotentials can be allocated to the HER as the dominating reaction. [48] After Ru-based CCM [53] Gas phase 0.46 0.90 0.93 CuÀ TiO 2 /NG based GDE [54] Near neutral (pH = 6.8) À 0.20 À 0.06 19.5 Cu-doped CNTs based GDE [55] Alkaline (pH = 9) 0.28 À 4.75 47.4 CuÀ Bi MOFs based GDE [15] Near neutral (pH = 6.8) blend solution causing densification of the membrane overlayer upon casting and solvent evaporation, as well as the largest water transport reported elsewhere. These results are attributed to the higher accessibility of CO 2 to the catalyst in the uncoated GDE, and confirmed that the membrane over-layer was posing an additional resistance to transport.…”

“…Ru-based CCM [53] Gas phase 0.46 0.90 0.93 CuÀ TiO 2 /NG based GDE [54] Near neutral (pH = 6.8) À 0.20 À 0.06 19.5 Cu-doped CNTs based GDE [55] Alkaline (pH = 9) 0.28 À 4.75 47.4 CuÀ Bi MOFs based GDE [15] Near neutral (pH = blend solution causing densification of the membrane overlayer upon casting and solvent evaporation, as well as the largest water transport reported elsewhere. [48] Therefore, this Cu/CS : PVA membrane layer generated the highest current densities generated of all MCE in Table 2, but the catalyst in metallic form seemed to be less accessible for CO 2 and its ionic forms, so the methanol production dropped, in favor of HER as dominant reaction.…”

“…One of the main issues is the fabrication of electrodes that provide productive and efficient transformation of CO 2 at low overpotentials. The effect of surface morphology on the CO 2 RR to alcohols or hydrocarbons has been studied in the form of Cucoated nanospikes, [12] nanowire [13] or metal-organic frameworks (MOFs, [14,15] among others. [5] Electrocatalysis is an interfacial phenomenon, where the relative ratio of CO 2 and H 2 (H + ) is dictated by the intrinsic selectivity of surface active sites and the local concentration of reaction compounds involved in the different rate-controlling stages.…”

“…[8][9][10][11] Besides composition, surface structure and morphology also plays a relevant role in electrode performance. The effect of surface morphology on the CO 2 RR to alcohols or hydrocarbons has been studied in the form of Cucoated nanospikes, [12] nanowire [13] or metal-organic frameworks (MOFs, [14,15] among others. The micro and meso structure of the electrode determines the diffusional gradients under steadystate conditions.…”

Restructuring Metal–Organic Frameworks to Nanoscale Bismuth Electrocatalysts for Highly Active and Selective CO2 Reduction to Formate

“…[ 13b–d ] In very recent publications, the electrocatalytic CO 2 reduction properties of catalysts based on bismuth containing MOFs were investigated. [ 14 ] In a study by Albo et al, the stoichiometry of Bi‐ and Cu‐based MOF mixtures, consisting of Bi(1,3,5‐benzenetricarboxylate) and Cu 3 (1,3,5‐benzenetricarboxylate) 2 , was found to determine the selectivity of the catalyst. [ 14a ] Their mixed‐metal system led to the conversion of CO 2 to mixtures of alcohols, formate, H 2 , and small amounts of C 2 H 4 and CO, but selectivity to one specific eCO 2 RR product was not optimized.…”