Conn Center for Renewable Energy Research, University of Louisville, Louisville, KY, 40292, USA.
Angew Chem Int Ed Engl. 2017 Mar 20;56(13):3645-3649. doi: 10.1002/anie.201612194. Epub 2017 Feb 23.
Electrochemical conversion of CO into energy-dense liquids, such as formic acid, is desirable as a hydrogen carrier and a chemical feedstock. SnO is one of the few catalysts that reduce CO into formic acid with high selectivity but at high overpotential and low current density. We show that an electrochemically reduced SnO porous nanowire catalyst (Sn-pNWs) with a high density of grain boundaries (GBs) exhibits an energy conversion efficiency of CO -into-HCOOH higher than analogous catalysts. HCOOH formation begins at lower overpotential (350 mV) and reaches a steady Faradaic efficiency of ca. 80 % at only -0.8 V vs. RHE. A comparison with commercial SnO nanoparticles confirms that the improved CO reduction performance of Sn-pNWs is due to the density of GBs within the porous structure, which introduce new catalytically active sites. Produced with a scalable plasma synthesis technology, the catalysts have potential for application in the CO conversion industry.
电化学将 CO 转化为甲酸等能量密集型液体，作为储氢材料和化学原料是可取的。SnO 是少数几种能以高选择性将 CO 还原为甲酸但需要高过电势和低电流密度的催化剂之一。我们发现，具有高密度晶界（GB）的电化学还原 SnO 多孔纳米线催化剂（Sn-pNWs）比类似的催化剂具有更高的 CO 到 HCOOH 的能量转换效率。HCOOH 的形成起始于较低的过电势（350 mV），并且在仅相对于 RHE 为-0.8 V 时达到稳定的法拉第效率约为 80%。与商业 SnO 纳米颗粒的比较证实，Sn-pNWs 改善的 CO 还原性能归因于多孔结构内 GB 的密度，这引入了新的催化活性位点。该催化剂采用可扩展的等离子体合成技术制备，具有在 CO 转化工业中应用的潜力。
