Rapid complete reconfiguration induced actual active species for industrial hydrogen evolution reaction

Abstract

Rational regulation of electrochemical reconfiguration and exploration of activity origin are important foundations for realizing the optimization of electrocatalyst activity, but rather challenging. Herein, we potentially develop a rapid complete reconfiguration strategy for the heterostructures of CoC2O4 coated by MXene nanosheets (CoC2O4@MXene) during the hydrogen evolution reaction (HER) process. The self-assembled CoC2O4@MXene nanotubular structure has high electronic accessibility and abundant electrolyte diffusion channels, which favor the rapid complete reconfiguration. Such rapid reconfiguration creates new actual catalytic active species of Co(OH)2 transformed from CoC2O4, which is coupled with MXene to facilitate charge transfer and decrease the free energy of the Volmer step toward fast HER kinetics. The reconfigured components require low overpotentials of 28 and 216 mV at 10 and 1000 mA cm−2 in alkaline conditions and decent activity and stability in natural seawater. This work gives new insights for understanding the actual active species formation during HER and opens up a new way toward high-performance electrocatalysts.

Ultrafast Combustion Synthesis of Robust and Efficient Electrocatalysts for High-Current-Density Water Oxidation

“…Durability also plays an imperative part in catalyst performance evaluation. , The electrolyte was refilled every 100 h. As indicated in Figure e and f, the optimized IF-Ni 150 mM electrode can work steadily at 100 mA cm –2 for up to 1500 h, even at a high current density of 1000 mA cm –2 without a significant voltage rise. The voltage in the first 5 min changes only 6 mV compared to the last 5 min, which demonstrates the ultralong stability of the catalyst and provides greater potential for its industrialization.…”

Efficient interlayer confined nitrate reduction reaction and oxygen generation enabled by interlayer expansion

“…Charge polarization between Fe and Ni atoms may facilitate the NTRR. [27][28][29][30][31] Electrochemical NTRR performance evaluation Then, electrochemical NTRR performance of α-Ni 1−x Fe x (OH) 2 samples is assessed using a three-electrode system, in which cathode and anode chambers are divided by the Nafion 117 membrane. Firstly, we screen the relationship of NTRR performance with Fe doping level using potentiostatic electrolysis at −0.6 V versus reversible hydrogen electrode (RHE).…”

“…[1][2][3] Ammonia is also deemed as a promising fuel and clean energy carrier, whose hydrogen content reaches 17.6 wt%. 4 Currently, industrial ammonia synthesis mainly relies on the century-old Haber-Bosch process, in which N 2 and steam-reformed H 2 are converted to NH 3 at elevated temperature (400-500 °C) and high pressure (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). 5 At present, ammonia production reaches 170 million tons per year, consuming about 1%-2% of the global annual energy supply and releasing 1.44% of global CO 2 emissions.…”

Inheritable Organic‐Inorganic Hybrid Interfaces with π–d Electron Coupling for Robust Electrocatalytic Hydrogen Evolution at High‐Current‐Densities

“…In the crystalline phase, lattice fringes with a spacing of 0.486 nm can be observed, corresponding to the (−002) plane of CoC 2 O 4 , which is slightly larger than the lattice spacing of standard CoC 2 O 4 . [36] The amorphous area corresponds to PANI. [33,35] The thickness of the PANI is significantly affected by the amount of aniline precursor.…”