Ruihong Guo,Yujuan Zhang,Xiutang Zhang,Hong Yang,Tuoping Hu
The development of efficient bifunctional catalysts is the key technology to replace oxygen evolution reaction (OER) with hydrazine oxidation reaction (HzOR) with lower theoretical potential to achieve high efficiency and energy-saving hydrogen production . In this work, the Co 0·52 Cu 0·48 /Cu@S–C (−1.3 V) composite with flower-like array was prepared by two-step electrodeposition coupled pyrolysis method. The electrochemical measurements showed that the driving voltages of the optimal composite for HzOR and hydrogen evolution reaction (HER) are respectively −118 mV and 47 mV at a current density (j) of 10 mA cm −2 . The excellent performance of Co 0·52 Cu 0·48 /Cu@S–C (−1.3 V) composite is attributed to the fact that the flower-like structure exposes more active areas and facilitates the diffusion of electrolyte, the strong electron interaction between Co 0·52 Cu 0·48 /Cu and S –C substrate, which can be verified by X-ray photoelectron spectroscopy (XPS), enhances the electrical conductivity , the Co 0·52 Cu 0·48 /Cu heterogeneous interface reduces the water dissociation barrier and facilitates the dehydrogenation kinetics of N 2 H 4 determined by density functional theory (DFT) calculations. Due to the excellent performance of Co 0·52 Cu 0·48 /Cu@S–C (−1.3 V), the overall hydrazine splitting (OHzS) electrolytic cell was constructed with Co 0·52 Cu 0·48 /Cu@S–C (−1.3 V) as electrodes. The results showed the voltages required by the cell are 36, 210 and 282 mV at the current density values of 10, 100 and 200 mA cm −2 respectively, showing that Co 0·52 Cu 0·48 /Cu@S–C (−1.3 V) can be used for energy-saving hydrogen production by hydrazine assisted water electrolysis.
Modifying the catalyst's electronic structure is essential for improving the hydrazine oxidation reaction (HzOR) and alkaline hydrogen evolution reaction (HER), but it is still very difficult. We have developed a new heterostructured electrocatalyst in this work using Ru nanosheets and NiCo layered double hydroxides (LDH). In-situ Raman and theoretical studies show that the heterostructure of Ru/NiCo LDH lowers absorption of hydrogen's Gibbs free energy and the d-band center of Ru/NiCo LDH (from −1.7250 to −1.3341 eV), causing the directed development of interfacial H 2 O (ΔG H* , from 1.65 to 0.23 eV). With an overpotential of 19 and 75 mV to achieve 10 and 100 mA cm −2 for HER, these beneficial characteristics provide the Ru/NiCo LDH with exceptional electrocatalytic capabilities. For HzOR, 10 and 100 mA cm −2 may be produced using just −118 and−112 mV, respectively. The Ru/NiCo LDH electrolyzer also only needs 22 and 223 mV to produce 10 and 100 mA cm −2 , respectively. This work lays the groundwork for developing bifunctional catalysts for the green hydrogen industry.
危险品化学品经营许可证（带存储）