Metal (Sn, Bi, Pb, Cd) in-situ anchored on mesoporous hollow kapok-tubes for outstanding electrocatalytic CO2 reduction to formate

Herein, mesoporous hollow kapok-tubes (denoted as MHKTs) is first used as carbon electrocatalyst for CO2 electroreduction that can selectively convert CO2 to formate without doping active elements, achieving the highest Faradaic Efficiency (FE) for formate at a potential range from −1.0 to −1.1 V vs. RHE (E = −1.0 V, FE = 48%; E = −1.1 V, FE = 50%). Moreover, MHKTs is also first used as new carbon support for loading metals in CO2 electroreduction, metals (Sn, Bi, Pb and Cd) in-situ anchored on MHKTs are all prepared via in-situ simple one-pot synthetic strategy. The four electrocatalysts Sn@MHKTs (E = −0.9 V, FE = 94%; E = −1.0 V, FE = 95%; E = −1.1 V, FE = 90%), Bi@MHKTs (E = −0.9 V, FE = 90.5%; E = −1.0 V, FE = 93%; E = −1.1 V, FE = 92%), Pb@MHKTs (E = −1.0 V, FE = 85%; E = −1.1 V, FE = 80%) and Cd@MHKTs (E = −0.9 V, FE = 71%; E = −1.0 V, FE = 74%; E = −1.1 V, FE = 70%) all exhibit high selectivity for electrocatalytic CO2 to formate at a wide potential range with low overpotential and high current density, respectively outperforming electrocatalysts synthesized under the same conditions that use traditional MWCNTs and rGO as carbon support (Sn@MWCNTs, Bi@MWCNTs, Pb@MWCNTs, Cd@MWCNTs; Sn@rGO, Bi@rGO, Pb@rGO, Cd@rGO). These outstanding performances of low cost metal@MHKTs electrocatalysts display great potential for large-scale using in CO2-to-formate process.