Charge redistribution on surface of Ru nanoparticle can significantly affect electrocatalytic HER activity. Herein, a double atomic-tuned RuBi SAA/Bi@OG nanostructure that features RuBi single-atom alloy nanoparticle supported by Bi-O single-site-doped graphene was successfully developed by one-step pyrolysis method. The alloyed Bi single atom and adjacent Bi-O single site in RuBi SAA/Bi@OG can synergistically manipulate electron transfer on Ru surface leading to optimum charge redistribution.
View Article and Find Full Text PDFSingle atom catalysts (SACs) have been widely studied in the field of CO electroreduction, but industrial-level current density and near-unity product selectivity are still difficult to achieve. Herein, a diatomic site catalysts (DASCs) consisting of Co-Cu hetero-diatomic pairs is synthesized. The CoCu DASC exhibits excellent selectivity with the maximum CO Faradaic efficiency of 99.
View Article and Find Full Text PDFMetal heterocyclic carbenes (M-NHCs) on the pore walls of a porous metal-organic framework (MOF) can be used as active sites for efficient organic catalysis. Traditional approaches that need strong alkaline reagents or insoluble AgO are not, however, suitable for the incorporation of NHCs on the backbones of MOFs because such reagents could destroy their frameworks or result in low reactivity. Accordingly, development of facile strategies toward functional MOFs with covalently bound M-NHCs for catalysis is needed.
View Article and Find Full Text PDFThe electrocatalytic conversion of CO into value-added chemicals is a promising approach to realize a carbon-energy balance. However, low current density still limits the application of the CO electroreduction reaction (CO RR). Metal-organic frameworks (MOFs) are one class of promising alternatives for the CO RR due to their periodically arranged isolated metal active sites.
View Article and Find Full Text PDFThe electroreduction of CO to value-added chemicals such as CO is a promising approach to realize carbon-neutral energy cycle, but still remains big challenge including low current density. Covalent organic frameworks (COFs) with abundant accessible active single-sites can offer a bridge between homogeneous and heterogeneous electrocatalysis, but the low electrical conductivity limits their application for CO electroreduction reaction (CO RR). Here, a 2D conductive Ni-phthalocyanine-based COF, named NiPc-COF, is synthesized by condensation of 2,3,9,10,16,17,23,24-octa-aminophthalocyaninato Ni(II) and tert-butylpyrene-tetraone for highly efficient CO RR.
View Article and Find Full Text PDFIt is still a great challenge to achieve high selectivity of CH in CO electroreduction reactions (CO RR) because of the similar reduction potentials of possible products and the sluggish kinetics for CO activation. Stabilizing key reaction intermediates by single type of active sites supported on porous conductive material is crucial to achieve high selectivity for single product such as CH . Here, Cu O(111) quantum dots with an average size of 3.
View Article and Find Full Text PDFWe report a facile but effective approach to construct a highly dispersed diatomic catalyst. A carbon-embedded diatomic Ni2 catalyst was synthesized from carbon black, polyaniline and nickel(ii) salts. The resulting catalyst exhibits excellent activity for the CO2 reduction reaction (CO2RR) at low Ni content with a faradaic efficiency of CO over 95% in the potential range from -0.
View Article and Find Full Text PDFIt is highly desired but challenging to achieve highly active single-atom Fe sites from iron-based metal-organic frameworks (MOFs) for efficient oxygen reduction reaction (ORR) due to the easy aggregation of iron species and formation of the inactive Fe-based particles during pyrolysis. Herein, a facile migration-prevention strategy is developed involving the incorporation of polyaniline (PANI) into the pores of iron porphyrinic-based MOF PCN-224(Fe) and followed by pyrolysis to obtain the single-atom Fe implanted N-doped porous carbons material PANI@PCN-224(Fe)-900. The introduced PANI inside the pores of PCN-224(Fe) not only served as protective fences to prevent the aggregation of the iron species during thermal annealing, but also acted as nitrogen sources to increase the nitrogen content and form Fe-N-C active sites.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs) are promising alternative precursors for the fabrication of heteroatom-doped carbon materials for energy storage and conversion. However, the direct pyrolysis of bulk MOFs usually gives microporous carbonaceous materials, which significantly hinder the mass transportation and the accessibility of active sites. Herein, N-doped carbon aerogels with hierarchical micro-, meso-, and macropores were fabricated through one-step pyrolysis of zeolitic imidazolate framework-8/carboxymethylcellulose composite gel.
View Article and Find Full Text PDFMetal-organic framework (MOF) derived carbon materials are promising for energy storage and conversion as they could inherit the advantages of MOF precursors, such as high porosity, large surface area and uniform heteroatom doping. Although the morphologies of MOF precursors have a significant effect on the properties of the resulting materials, up to now, there has been no systematic study on the relationship of the morphologies of MOFs and the properties of their pyrolized carbonaceous materials. Herein, three isomorphous imidazolate-based ZIF-7 materials with different morphologies (sphere, polyhedron and rod shape) have been selected as precursors and carbonized to obtain porous N-doped carbon materials with a tunable morphology, pore features and surface areas.
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