Ru−FeNi Alloy Heterojunctions on Lignin‐derived Carbon as Bifunctional Electrocatalysts for Efficient Overall Water Splitting

Abstract

Rational design of efficient, stable, and inexpensive bifunctional electrocatalysts for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER) is a key challenge to realize green hydrogen production via electrolytic water splitting. Herein, Ru nanoparticles and FeNi alloy heterojunction catalyst (Ru−FeNi@NLC) encapsulated via lignin‐derived carbon was prepared by self‐assembly precipitation and in situ pyrolysis. The designed catalyst displays excellent performance at 10 mA cm−2 with low overpotentials of 36 mV for HER and 198 mV for OER, and only needs 1.48 V for overall water splitting. Results and DFT calculations show the unique N‐doped lignin‐derived carbon layer and Ru−FeNi heterojunction contribute to optimized electronic structure for enhancing electron transfer, balanced free energy of reactants and intermediates in the sorption/desorption process, and significantly reduced reaction energy barrier for the HER and OER rate‐determining steps, thus improved reaction kinetics. This work provides a new in situ pyrolysis doping strategy based on renewable biomass for the construction of highly active, stable and cost‐effective catalysts.

Highly Efficient Conversion of Lignin into Diethyl Maleate Catalyzed by Molybdenum-Based Hybrid Catalysts

“…Therefore, there is a pressing need for the transformation of lignin using low-cost heterogeneous catalysts. Nitrogen-doped carbon-loaded metal materials have garnered significant interest due to their high concentration of oxygen-containing groups, excellent dispersibility, easy modification reactivity, and favorable properties. − Moreover, the addition of N dopants can improve the catalytic activity of nitrogen-doped carbon-supported metal catalysts by enhancing the conductivity between metal sites and carbon substrates …”

Bi-Activation Engineering of Lignin-Derived Porous Carbon Adsorbent for Highly Efficient Water Purification

“…In recent years, a number of adsorbents have been developed to fulfill this purpose, including carbon-based materials (activated carbon (AC) being the most representative), − metal–organic frameworks (MOF), , silica, and polymers, whereas carbon-based materials have garnered considerable attention due to their large specific surface area, superior chemical stability, low toxicity, and tunable pore structure. , Lignocellulose can be a reliable and long-lasting source of carbon precursors, and the adoption of these ecologically acceptable precursors can alleviate the difficulties associated with the treatment of solid waste and lower the price of the raw materials required to produce AC. − …”

Tunable and Functional Deep Eutectic Solvents for the Highly Selective Production of Methoxy-Free Lignin Monomers via Fast Pyrolysis

“…Due to the limitations of fossil energy in terms of environmental pollution and reserves, renewable biomass resources have gradually attracted widespread attention. − As one of the three major components of lignocellulose, lignin is the most abundant aromatic polymer in nature, which is a complex three-dimensional network polymer formed by the biological polymerization of natural aromatic phenylpropane monomer precursors. − The rich in aromatic structures in lignin, such as guaiacyl, syringyl, and p -hydroxyphenyl, mean that lignin has great potential to produce high-value chemicals, such as phenolic compounds. − However, it is difficult to be efficiently converted into high-value chemicals due to its high degree of polymerization and complex structure. To utilize lignin efficiently, many strategies of lignin depolymerization have been gradually explored and developed, such as hydrogenolysis, acid–base catalytic depolymerization, − bioconvension, and pyrolysis .…”