Replacing the oxygen evolution reaction (OER), which is of high energy consumption and slow kinetics, with the more thermodynamically favorable reaction at the anode can reduce the electricity consumption for hydrogen production. Here we developed a lignin-assisted water electrolysis (LAWE) process by using Ti/PbO2 with high OER overpotential as the anode aimed at decreasing the energy consumption for hydrogen production. The influence of key operating parameters such as temperature and lignin concentration on hydrogen production was analyzed. Compared with alkaline water electrolysis (AWE), the anode potential can be decreased from 0.773 to 0.303 (V vs. Hg/HgO) at 10 mA/cm2 in LAWE, and the corresponding cell voltage can be reduced by 546 mV. With increasing the temperature and lignin concentration, current density and H2 production rate were efficiently promoted. Furthermore, the anode deactivation was investigated by analyzing the linear sweep voltammetry (LSV) and cyclic voltammetry (CV) tests. Results showed that the anode deactivation was affected by the temperature.
During the electrochemical preparation process, the electron transport rate in the PbO2 active layer could be greatly increased resulting from reduction in the oxidation of the Ti substrate, which effectively improved the service life and catalytic degradation efficiency of the PbO2 Dimension Stable Anode (PbO2 DSA) electrode. Through adding nano-acetylene black (ACET) and polyvinyl pyrrolidone (PVP) into the plating solution, an ACET doped Ti/PbO2 electrode was successfully prepared via an anodic oxidation method. Results of field emission scanning electron microscope (FESEM), diffraction of X-rays (XRD), transmission Electron Microscope(TEM) and X-ray photoelectron spectroscopy (XPS) characterization indicated that 2.10 ∼ 2.75 wt% of ACET doping amount hardly changed the morphology and lattice constant of the PbO2 electrode. With electrochemical alternating current impedance spectroscopy (EIS) and cyclic voltammetry (CV), it confirmed that ACET reduced the charge transfer impedance (Rct) of the PbO2 electrode up to 95%, and restrained the potential of oxygen evolution reaction(OER). With the increase of electron transport rate, the generation rate of hydroxyl radicals (·OH) on the electrode surface was enhanced significantly. Compared with the Ti/PbO2 electrode, the ACET-doped Ti/PbO2 electrode exhibited higher electrocatalytic efficiency to phenol degradation. During the degradation process, the consumption of time and energy could be reduced by 33% and 34%, respectively. At the same current density, the required voltage for preparing the ACET-modified Ti/PbO2 electrode was much lower. In the assistant of lower deposition voltage, the ACET-doped Ti/PbO2 electrode possessed a stronger binding force to Ti substrate, and meanwhile obtained a longer lifespan.
Electrochemical methods for catalytic furfural conversion have drawn significant interest in both academic and industrial research communities. Paired electrocatalytic conversion has been identified as a promising strategy for reducing energy consumption and promoting carbon neutrality. To optimize product distribution and conversion efficiency, we have developed a divergent paired electrochemical upgrading approach for furfural in acidic environments, with a focus on prioritizing strong gas evolution reactions and product transformations. The high electrocatalytic activity of CuSn/CuF@Cu prepared by electrodeposition can effectively inhibit the hydrogen evolution. The performance of the electrocatalysts and the pathways of electrocatalytic hydrogenation (ECH) of furfural to 2-methylfuran (MF) were investigated by combination of experiments and the density functional theory (DFT) calculations. A stable Ti/PbO 2 electrode with high oxygen evolution overpotential was prepared for anodic electrocatalytic oxidation (ECO) and the product transformation route was described. The conversion of furfural to maleic acid (MA) and MF in acidic environment was successfully achieved. In the paired electrosynthesis system, the electrons generated from anodic ECO of furfural are utilized in valuable and controllable cathodic ECH. It significantly and continuously reduces the power cost associated with renewable energy sources and further promotes the development of biomass electrochemical conversion.