Integrated Capture and Electroreduction of Flue Gas CO₂ to Formate Using Amine Functionalized SnO_x Nanoparticles

Abstract

Flue gas from fossil fuel combustion contributes significantly to CO2 emissions. Due to the low CO2 concentration and the existence of reactive O2 in the flue gas, direct flue gas CO2 electrochemical conversion is a challenging task. Here we integrated both CO2 capture and electrochemical conversion into CO2 enriching catalysts by grafting alkanolamines on a tin oxide surface, which can electrochemically reduce simulated flue gas (SFG, 15% CO2, 8% O2, 77% N2) to formate. Maximum formate Faradaic efficiency of 84.2% has been reached by diethanolamine modified tin oxide (DEA–SnO x /C) at −0.75 V vs RHE with partial current density of 6.7 mA·cm–2 in 0.5 M KHCO3 under simulated flue gas atmosphere. Surface amino groups not only enrich CO2 locally but also inhibit O2 reduction, and in situ infrared (in situ IR) spectroscopy confirmed that amino groups accelerate CO2 reduction by promoting the formation of key intermediates (OCHO–*).

Activity switching of Sn and In species in Heusler alloys for electrochemical CO2 reduction

“…In both cases, FE for CO generation (FE CO ) was less than 10% and the FE for H 2 generation (FE H2 ) was 9% and 20% for In and Sn particles, respectively. This tendency was essentially similar to reported results for pure In and Sn electrodes, 28,29 and other studies using In 30 or Sn 31,32 catalysts. For the Heusler alloy Ni 2 MnIn, the main CO 2 RR product was also formate (FE formate = 66%) while CO and H 2 were also detected (FE CO = 11%, and FE H2 = 21%).…”

Development of catalysts and electrolyzers toward industrial-scale CO2electroreduction

“…63 Moreover, the morphologies and structures of SnO x also inuence the reduction activity. [64][65][66] A wavy structural SnO 2 network (Fig. 4b) showed a higher catalytic performance than commercial SnO 2 nanoparticles, with FE HCOOH of 87.4% and current density of 22 mA cm À2 at an applied potential of À1.0 V vs. RHE.…”

Rational Manipulation of Intermediates on Copper for CO2 Electroreduction Toward Multicarbon Products

“…In this situation, cofeeding CO 2 with other chemicals can decrease the cost of CO 2 purification and/or create high-value products, in turn improving the technical economy of the catalytic systems. For example, flue gas is a potential source of CO 2 and can be adopted to reduce the purification cost; however, more deliberate catalyst design and pressurization are required to overcome the competition reaction caused by the oxidizing gases [186,187]. Besides, the formation of C-N compounds by the coelectrolysis of CO 2 and nitrogencontaining reactants also holds great promise [188][189][190].…”