The gluconic acid electroreduction reaction (GAER) coupled with renewable energy is a carbon-free and highly promising biomass utilization route. However, this process still suffers from low conversion efficiency and poor selectivity due to the competitive hydrogen evolution reaction. Some organic amine molecules can not only serve as surfactants to synthesize noble-metal based catalysts with special morphologies, but also can further optimize the catalytic activity of metal surfaces by modulating their electronic structure. Herein, polyethyleneimine (PEI) functionalized gold nanodendrites (PEI-Au NDs) are applied as an efficient electrocatalyst for GAER, in which the production rate and Faradaic efficiency of glucose on PEI-Au NDs reaches to 9.86 mu g h-1 mgcata 0.80 V vs. RHE, respectively. The mechanism study through density functional theory calculations reveals that the adsorbed PEI molecule exhibits an electron donating-effect, which can promote the adsorption process of gluconic acid molecules on the Au(1 1 1) plane and the subsequent reduction process. This work offers a novel pathway to rational regulate the adsorption properties and electronic structures of noble metal-based electrocatalysts through chemical functionalization strategy.

The selective electrochemical conversion of glycerol into value-added products is a green and sustainable strategy for the biomass utilization. In this work, Au nanowires (Au-NW) modified with polyethyleneimine (PEI) molecule (Au-NW@PEI) is obtained by an up-bottom post-modification approach. Physical characterization, molecular dynamics simulation and density functional theory demonstrate that the loose-packed PEI monolayer firmly and uniformly distribute on the Au-NW surface due to the strong Au-N interaction. Electrochemical experiments and product analysis display that PEI modification significantly enhance the electro-activity of Au-NW for the glycerol electro-oxidation reaction (GEOR) due to the electronic effect. Meanwhile, the steric hindrance and electrostatic effect of PEI layer make the optimizing adsorption of intermediates possible. Therefore, the selectivity of C3 product glyceric acid over Au-NW@PEI is increased by nearly 20%. The work thus indicates that the rational design of metal-organic interface can effectively elevate the electro-activity and selectivity of Au nanostructures, which may have wide application in biomass development.

Carbonic anhydrase (CA) is bound to a dendritic porous copper foam (3D-Cu) via electrostatic interaction to form a biohybrid (CA/3D-Cu), which exhibits high selectivity and Faraday efficiency in the electroreduction of carbon dioxide (CO2) to formic acid (selectivity of 98.7%, Faraday efficiency of 82.1%) due to the large specific surface area of the 3D-Cu and the ultra-high CO2 hydration capacity of CA. Carbonic anhydrase (CA) is bound to a dendritic porous copper foam (3D-Cu) via electrostatic interaction to form a biohybrid (CA/3D-Cu), which exhibits high selectivity and FE in the electroreduction CO2 to formic acid due to high specific surface area and ultrahigh CO2 hydration capacity of CA.

Designing cost-efficient and active electrocatalysts are very crucial for their practical implementation in elec-trochemical energy conversion systems. Herein, a handy template-post phosphatization approach is adopted to achieve ultra-thin CoNi0.2P nanosheets attached to nickel foam (termed as CoNi0.2P-uNS/NF) nanohybrids. Profiting from ultra-thin construction and the optimization of electronic structure, CoNi0.2P-uNS/NF exhibits high electroactivity for hydrogen evolution reaction (HER), which only needs an overpotential of 43 mV to obtain the current density of 10 mA cm-2. Additionally, CoNi0.2P-uNS/NF also reveals prominent electroactivity for ethylene glycol oxidation reaction (EGOR) in an alkaline environment due to the surface electrochemical reconstruction. Additionally, CoNi0.2P-uNS/NF also reveals similar high electroactivity for glycerol and furfural derivatives oxidation reaction, revealing its potential as a composition-controlled platform catalyst. For practical application, CoNi0.2P-uNS/NF||CoNi0.2P-uNS/NF electrolyzer is assembled to directly electrolyze the hydrolysate of polyethylene terephthalate (i.e., the mixture of terephthalate and ethylene glycol) for the co-generation of formate and hydrogen, accompanying with lower integral electrolytic voltage (1.24 V) than traditional water splitting (1.53 V) at current density 50 mA cm-2. This work expands the territory for energy-saving co-generation of hydrogen and value-added chemical products.

Electrocatalysis is an interface-dominated process, in which the activity of the catalyst highly relates to the adsorption/desorption behaviors of the reactants/intermediates/products on the active sites. From the perspective of catalyst design, the chemical functionalization design on noble metal surfaces will inevitably affect the reaction process, which is considered to be one of the effective strategies to tune the electrocatalytic performance of noble metal nanocrystals. Polyamines (PAM) with high stability and good coordination ability have been widely studied as important functional molecules. In this account, we first introduce the PAM-assisted synthesis mechanism of noble metal nanocrystals, which provides a theoretical basis and guidance for their design and optimization with controllable morphology. Then, the effects of adsorbed PAM on the electronic structure, geometric structure, electrode/electrolyte interface structure and catalytic reaction pathway of noble metal-based catalysts are specifically described. The internal mechanism of noble metal-PAM interfacial effect increasing catalyst activity and selectivity is stated, and the latest research progress of PAM functionalized catalysts applied in important reactions is listed, such as hydrogen evolution reaction, oxygen reduction reaction, formic acid oxidation reaction, and nitrate reduction reaction, and so on. These findings open a new avenue for constructing advanced electrocatalysts based on inorganic/organic polymer-mediated interface engineering in various energy-related catalysis/electrocatalysis fields. Finally, the current challenges and future prospects of PAM molecule functionalized noble metal electrocatalysts are proposed.

Electrostatically assembled ultrathin rhodium nanosheet-gold nanowire nanocomposites (Rh-Au CNSs) were used as an advanced electrocatalyst for the methanol oxidation reaction, which revealed a mass activity of 355 mA mgRh-1 at 0.607 V potential, much higher than single metal Rh nanosheets (273 mA mgRh-1) and commercial Rh nanoparticles (165 mA mgRh-1).