ИСТИНА

The development of efficient catalytic system for elctroreduction of CO2 to intermittent energy fuels has received noticeable attention from the scientific community all over the globe. Ag-based catalysts have drawn great attention due to its product selectivity towards CO formation in CO2 reduction reaction (CO2RR) [1]. On the other hand, the use of room-temperature ionic liquids (ILs) can decrease the CO2RR overpotential[2]. Herein, we demonstrated the enhanced catalytic activity of a novel nanostructured Ag electrode in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]). The nanostructured and highly porous Ag catalyst was prepared via additive assisted electrodeposition approach. Deposition was done galvanostatically for 20 s at current density of –3 Acm−2. The Ag catalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). It represented a Ag foam, consisting of nanorods (NRs) with diameters in the range of 50 to 100 nm (Fig. 1). The activity of the Ag NRs electrode was demonstrated by cyclic voltammetry (CV) to be significantly increased as compared to a Ag foil electrode in pure IL and with water addition (XH2O~20%). Using Ag NRs, we achieved highly selective CO production (Faradaic efficiency FE CO was nearly 100%) in a relatively broad potential window of 0.4 V in [BMIm][BF4]. Furthermore, to check the stability of the catalyst, we performed long-term electrolysis. For 5 hours, current density did not change and FECO remained ca. 100%. No structural changes in Ag NRs were revealed by identical location SEM characterization that was done before and after the electrolysis.