Controlled synthesis of a Bi₂O₃–CuO catalyst for selective electrochemical reduction of CO₂ to formate

Abstract

The electro-reduction of CO2 to produce energy sources has been considered as a visionary pathway with the help of renewable electricity, which can achieve carbon neutrality and mitigate global warming.

Curved Surface Boosts Electrochemical CO2 Reduction to Formate via Bismuth Nanotubes in a Wide Potential Window

“…Specifically, the low activity and selectivity of Bi bulk powder are due to the insufficient surface active sites derived from the large-sized particles (Figure S5). Bi NSs exhibit high activity mainly due to the low-coordinated sites of nanosheets . However, as the applied potential becomes more negative than −1.1 V, the mass transfer rate of CO 2 in the electrolyte reaches its limit, causing the decreased selectivity for formate (Figure c).…”

“…Bi NSs exhibit high activity mainly due to the lowcoordinated sites of nanosheets. 57 However, as the applied potential becomes more negative than −1.1 V, the mass transfer rate of CO 2 in the electrolyte reaches its limit, causing the decreased selectivity for formate (Figure 3c). For Bi NTs, the nanosized shape ensures the large quantity of the active sites and high CO2RR activity and the highly curved surface of the nanotube can ascend the concentrate of CO 2 near the active sites (FIRC effect).…”

Noble-Metal-Free Multicomponent Nanointegration for Sustainable Energy Conversion

“…Secondary metal doping and metallic alloying are well-established tactics in structural alteration and structure–activity relationships that have been vastly studied by numerous combinations of CO 2 RR-active metals, specifically Cu. − Distinctively, multimetal oxide combinations show a promising opportunity for further improvement in the field. Interface tuning in metal oxide/metal oxide hybrids is among the potential routes for heterostructuring of CO 2 RR catalysts that mainly relies on optimizing the catalytic synergy between different metal oxides, stabilizing the adsorption, and regulating the binding strength of CO 2 RR intermediates of interest. − However, interface engineering of metal oxides in multicomponent systems has been rarely reported. Geioushy et al fabricated the multicomponent ZnO@Cu 2 O@graphene heterostructure by a wet-chemistry synthesis for the selective conversion of CO 2 to n -propanol .…”

CO2 electroreduction to formate: Continuous single-pass operation in a filter-press reactor at high current densities using Bi gas diffusion electrodes

“…Very recently, bismuth has started to be considered as a promising electrocatalytic material for the CO2 electrocatalytic reduction to obtain formate at lower potentials than other metals, with a rapidly growing number studies using Bi in different forms . Firstly, Zhang et al [42] described the use of BiOCl nanosheets under ambient conditions in the electrochemical conversion of CO2 to give formate with a maximum faradaic efficiency (FE) of 92% and a current density (j) of 3.7 mA•mg -1 at -1.5 V. Additionally, Zhong et al [43] studied the electrochemical performance for CO2 towards formate using bismuth dendrites on treated carbon paper as electrocatalyst in the working electrode, achieving a FE of 96.4% with a j of 15.2 mA•cm -2 at -1.8 V. More recently, the latest studies have performed CO2 electrochemical conversion to formate working with different electrode configurations: electrodes based on bismuth nanoparticles synthesized on cupper surface [44,45,65,66]; bismuth nanoparticles synthesized on titanium substrate [46] and cupper substrate [47]; oxide-derived Bi films [48][49][50][51][52]63]; Bi nanosheets [53,54,64] or carbon-supported Bi nanoparticles [55]. All these studies above mentioned have been carried out in an aqueous bicarbonate medium with the exception of Zhang et al [56] and Atifi et al [57], which were done in a non-aqueous medium such as MeCN.…”

“…In the H-type configuration, both compartments are separated by a piece of membrane (e.g. Nafion 115 [42,43,58] , Nafion 117 [44,46,49,53,55,59] or Nafion 212 [51,56,57,60,65]), but the catholyte and the anolyte are not pumped to their respective compartments of the electrochemical cell during the CO2 electroreduction to give formate. High values of FE have been obtained, around 90 % (see Table S1 in the Supporting Information).…”