Interfacial engineering of metallic rhodium by thiol modification approach for ambient electrosynthesis of ammonia
Meng Jin, Xinyuan Zhang, Xian Zhang, Hongjian Zhou, Miaomiao Han, Yunxia Zhang, Guozhong Wang, Haimin Zhang
Abstract
Here we report a vapor-phase reaction approach to fabricate rhodium(I)-dodecanethiol complex coated on carbon fiber cloth (Rh(I)-SC12H25/CFC), followed by low-temperature pyrolysis to achieve dodecanethiol modified Rh (Rh@SC12H25/CFC) for electrocatalytic nitrogen reduction reaction (NRR). The results demonstrate that after pyrolysis for 0.5 h at 150 °C, the obtained Rh@SC12H25/CFC-0.5 exhibits excellent NRR activity with an NH3 yield rate of 121.2 ± 6.6 µg·h−1·cm−2 (or 137.7 ± 7.5 µg·h−1·mgRh−1) and a faradaic efficiency (FE) of 51.6 ± 3.8% at −0.2 V (vs. RHE) in 0.1 M Na2SO4. The theoretical calculations unveil that the adsorption of dodecanethiol on the hollow sites of Rh(111) plane is thermodynamically favorable, effectively regulating the electronic structure and surface wettability of metallic Rh. Importantly, the dodecanethiol modification on Rh(111) obviously decreases the surface H⋆ coverage, thus inhibiting the competitive hydrogen evolution reaction and concurrently reducing the electrocatalytic NRR energy barrier.