Amorphization of Metal Nanoparticles by 2D Twisted Polymer for Super Hydrogen Evolution Reaction

Abstract

Hydrogen generation by electrolysis of water in an alkaline solution is a promising technology for clean hydrogen energy. Amorphous materials show much better performance than their crystalline counterparts. However, it is still challenging to design amorphous metal materials. Here, a series of amorphous transition metal nanoparticles (NPs) is successfully synthesized using a twisted covalent organic network (CON) that can provide twisted carbon layers as well as asymmetrically distributed nitrogen. With the fixed monomer pore, a low loading amount of RuCl3 results in amorphous‐only Ru nanoclusters (NCs, 1.5 nm), while a high content of RuCl3 leads to crystalline dominant Ru NPs (3 nm). The mixed phased Ru‐CON catalyst for the hydrogen evolution reaction (HER) shows extremely low overpotential at 10 mA cm–2 (12.8 mV in 1.0 m KOH) and superior stability (after 100 h test, current loss 5.3% at 75 mA cm–2). More importantly, amorphous‐only Ru‐CON with smaller Ru NCs shows much better mass activity and considerable stability compared to mixed‐phase Ru‐CON materials since amorphous Ru NPs can provide more active sites than in their crystalline state. With this strategy, amorphous Fe NPs and Ir NPs are successfully prepared for extended applications, and the HER activities are reported.

Efficient Nitrate Conversion to Ammonia on f-Block Single-Atom/Metal Oxide Heterostructure via Local Electron-Deficiency Modulation

“…22 The durability of Gd SA -D-NiO 400 for the NitRR was further accessed by 15 consecutive electrolysis cycling tests at −0.1 V vs RHE (Figure 4h and Figure S35). 3,34,35 The NH 3 yield rate and FE remained stable with slight fluctuations, suggesting the excellent stability and robustness of the Gd SA stabilized on the defective NiO. Additionally, the in situ/operando Raman spectrum of Gd SA -D-NiO 400 during NitRR was tested.…”

Reactive template‐derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

“…These negative values indicate that the water adsorption is thermodynamically favorable on these surfaces. Furthermore, the highest water adsorption energy of the CoP/CoO heterostructure indicates that the establishment of the CoP/CoO heterointerface is highly beneficial for water affinity and thus results in the accelerated Volmer step in alkaline electrolytes 57 . The Gibbs free energies of hydrogen (Δ G H* ) on different surfaces are further calculated to determine the HER activity.…”

Atomically Dispersed Metal–Nitrogen–Carbon Catalysts with d-Orbital Electronic Configuration-Dependent Selectivity for Electrochemical CO2-to-CO Reduction

“…However, its practical application has been significantly challenged by its uncontrollable product selectivity in electrochemical CO 2 RR due to the complicated reaction pathways and overdiversified products. Given that CO is the most common and simplest product, which is of high value in the C 1 chemical product chain, the electrochemical CO 2 -to-CO reduction reaction with only two electrons getting involved in the CO 2 RR could achieve high activity and high selectivity as expected. − In the past years, some noble-metal (e.g., Ag, − Au, − etc. )-based catalysts have revealed excellent electrochemical performances for CO 2 RR, which could effectively reduce CO 2 to CO at relatively low overpotentials.…”