Conversion of CO2 to chemical feedstocks over bismuth nanosheets in situ grown on nitrogen-doped carbon†
Abstract
The conversion of CO2 to value-added chemicals represents an attractive approach for CO2 utilization. Formate and methanol are sustainably valuable fuels and chemical feedstocks. However, the CO2 reduction reaction (CO2RR) suffers from unsatisfactory activity, low faradaic efficiency (FE) and inadequate durability. In this study, ultrathin bismuth nanosheets (NSs) and Bi NSs grown on nitrogen-doped ordered mesoporous carbon (OMC-N) are prepared from in situ transformation of atomic-thick Bi2O2Se and Bi2O2Se/OMC-N. Bi NSs enable efficient formate production with a large current density (51 mA cm−2 at −1.0 VRHE) and excellent selectivity (FE ≈ 90%). Interestingly, Bi NSs/OMC-N catalyzes the conversion of CO2 to formate and methanol simultaneously with maximum FEformate (70%) and FEmethanol (67%), and long-term stability (35 h). The composition produces 9.15 and 8.00 μmol cm−2 h−1 for formate and methanol at −0.67 VRHE, respectively, and methyl formate could be further prepared from the above products. Moreover, the generated Bi NSs achieve 288 mA cm−2 at −0.61 VRHE within a flow cell. Theoretical studies reveal that the activity for methanol is rationalized as the outcome of abundant pyridinic-N sites that stabilize the *COOH intermediate. Our study unveils the potential of hierarchical Bi NSs/OMC-N for an efficient and stable CO2RR to produce chemical feedstocks.