Sanhe Power Generation Co.,Ltd.
Utilization and Storage (CCUS) Technology for Coal-based Energy
HebeiProvince Coal-fired Power Station Pollution Prevention and Control Technology Innovation Center
State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology

利用新能源电能电催化还原二氧化碳(CO2)技术能在减排降碳过程将CO2转化为增值化学品,有广阔应用前景,在多种还原产物中,甲酸(HCOOH)易储存和运输,储氢密度高,应用前景好。氧化锡(SnO2)电催化材料成本低、毒性小,且SnO2用于电催化还原CO2制HCOOH选择性高。而在电催化还原的工业化中,合理的电解池结构有重要意义。为探究更合理的电解池结构,提出一种自制的多层堆栈式电解池,将通过火焰喷雾热解方法制备的SnO2纳米颗粒作为电催化剂,进行电催化还原CO2研究。探究电解池的阴极-阳极间距、电解液流速、电解液浓度及电极堆栈数目等参数对电催化性能影响。试验结果显示:阴极-阳极距离越小,电能损耗越少,电催化还原CO2性能更佳;电解液的流速对催化剂还原性能无明显影响,但过大的流速使反应的电流密度产生大的波动;在电解液浓度小于1mol/L时,催化剂对HCOOH的选择性随着电解液浓度增加而增加,而在电解液浓度大于1mol/L时,各产物的选择性趋于稳定;电极堆栈排放时,电流密度略下降,但整体法拉第效率和HCOOH的法拉第效率均所提高,并对析氢反应有较明显抑制作用。使用堆栈电解池可减小电荷转移电阻及扩散电阻。对于该堆栈电解池,在阴极-阳极间距10mm、施加电位-1.2Vvs.RHE、KHCO3浓度1mol/L下,SnO2在堆栈条件对HCOOH的法拉第效率达37.53%,且总的法拉第效率达75.83%。结果表明:使用堆栈电解池可提升催化剂催化性能,提升目标产物的选择性。

The electrocatalytic reduction of carbon dioxide (CO) using new energy and electrical energy can convert CO into value-added chemicals while reducing carbon emissions, which has broad application prospects. Among the various reduction products, formic acid(HCOOH) is easy to store and transport, with a high storage density of hydrogen. Tin oxide ( SnO ) electrocatalytic materials arelow-cost and less toxic, while SnO is highly selective for HCOOH when used for electrocatalytic reduction of CO.In the industrializationof electrocatalytic reduction, a reasonable electrolytic reactor structure is of great significance. To explore a more reasonable electrolytic reactor structure, this paper proposes a homemade multilayer stacked electrolytic reactor, in which SnO nanoparticles prepared by flamespray pyrolysis method are used as electrocatalysts for electrocatalytic reduction of CO.The effects of parameters such as cathode-anodespacing, electrolyte flow rate, electrolyte concentration and the number of electrode stacks on the electrocatalytic performance of the electrolytic cell were investigated. The experimental results show that: the closer the cathode-anode distance is, the lower the electrical energyloss is, and the catalyst has better catalytic performance; the flow rate of the electrolyte has no significant effect on the reduction performance of the catalyst, but when the flow rate is too fast, the current density of the reaction produces a more drastic fluctuation. When theelectrolyte concentration was less than 1 mol/ L, the selectivity of the catalyst for HCOOH increased with the increase of the electrolyte concentration, whereas the selectivity of the catalyst for each product stabilized at the electrolyte concentration of more than 1 mol/ L.The current density decreased slightly when the electrodes were placed in stacks, but the overall Faraday efficiency and the Faraday efficiency of HCOOH both increased, and the hydrogen precipitation reaction was suppressed more significantly. The charge transferresistance and diffusion resistance were reduced when using a stack electrolytic reactor. The optimum Faraday efficiency for HCCOHof SnO under stack conditions reaches 37.53% and the total Faraday efficiency reaches 75.83% with the cathode - anode spacing of10 mm, the applied potential of -1.2 V vs. RHE, and the KHCO concentration of 1 mol/ L. The results indicate that the catalytic performance of the catalyst and the selectivity of the target products can be enhanced by using a stacked electrolytic reactor.

湖北省重点研发计划资助项目(2021BCD003);河北省重点研发计划资助项目(22373708D)

魏书洲,谭舒婷,熊卓,等.基于堆栈电解池的纳米SnO2电催化CO2还原试验[J].洁净煤技术,2024,30(8):99-106.

WEI Shuzhou,TAN Shuting,XIONG Zhuo,et al.Experimental study of electrocatalytic CO2 reduction by nano-SnO2basedon stacked electrolytic reactor[J].Clean Coal Technology,2024,30(8):99-106.