MoS2 monolayer catalyst doped with isolated Co atoms for the hydrodeoxygenation reaction

Abstract

*Correspondence to: edman.tsang@chem.ox.ac.uk.The conversion of oxygen-rich biomass into hydrocarbon fuels requires efficient hydro-deoxygenation catalysts during the upgrading process. However, traditionally prepared Co-MoS 2 catalysts, although efficient for hydro-desulfurisation, are not appropriate due to their poor activity, sulfur loss and rapid deactivation at elevated temperature. Here, we report the synthesis of MoS 2 monolayer sheets decorated with isolated Co atoms through covalent bonding of Co to sulfur vacancies on the basal planes that, when compared to conventionally prepared samples, exhibit superior activity, selectivity and stability for the hydro-deoxygenation of 4-methylphenol to toluene. The higher activity, allows the reaction temperature to be reduced from the typically used 300 o C to 180 o C and thus allows the catalysis to proceed without sulfur loss and deactivation. Experimental analysis and density functional theory calculations reveal a large number of sites at the interface between the Co and Mo atoms on the MoS 2 basal surface and we ascribe the higher activity to the presence of sulfur vacancies that are created local to the observed Co-S-Mo interfacial sites.

High‐Resolution Electrochemical Mapping of the Hydrogen Evolution Reaction on Transition‐Metal Dichalcogenide Nanosheets

“…MoS 2 is one of the most promising precious raremetal-free catalysts for the hydrogen evolution reaction (HER). [1] To improve the catalytic activity of MoS 2 ,s ignificant efforts have been made in terms of conductivity improvement, [2] chemical doping, [3] phase transition, [4] strain, [5] and defect engineering. [6] However, most of the research characterizes the macroscopic catalytic activity of al arge number of MoS 2 nanosheets;q uantitatively identifying and characterizing catalytically active sites in MoS 2 are critically important for understanding the catalysis of MoS 2 .…”

A machine perspective of atomic defects in scanning transmission electron microscopy

“…Various grain boundaries [13][14][15][16][17][18][19][20][21][22][23][24][25] show distinct optical, electrical, magnetic, and catalytic properties. Herein, structural defects or external dopants are able to endow a broad range of promising applications in 2D materials based on the defect topology and density, such as nanoelectronics, 26 optoelectronics, 26 valleytronics, 27 catalysis, 28,29 and so on. In most cases, various types of structural defects coexist in one sample, and defect density varies in different locations.…”

Metal‐Sulfide Catalysts Derived from Lignosulfonate and their Efficient Use in Hydrogenolysis

“…Biomass hasb een extensivelyi nvestigateda sasource of renewable fuels and chemicals, [1][2][3] with the development of competitive biorefineries requiring efficient processes able to valorize all components in biomass. [1] The utilization of cellulose and hemicellulose to produce fuels and chemicals is a maturet echnology, [4][5][6] whereas utilization of the more recalcitrant biopolymer,l ignin, remains challenging despite excellent progress.…”

“…[40][41][42][43] Carbon-supported metal-sulfide catalysts have been obtained from atraditional multistepp rocess comprising incipient wetness, co-impregnationo na ctivated carbon, and sulfidization in as ubsequent step under af low of H 2 S/H 2 [36,44,45] or through heat treatment with sulfur-containing organics, that is, dimethylsulfide [37] or thiourea. [2] To bypasst he sulfidation step, we decided to use LS as precursor to synthesize highly dis-Catalytic lignosulfonate valorization is hampered by the in situ liberation of sulfur that ultimately poisons the catalyst. To overcome this limitation, metal sulfide catalysts were developed that are able to cleave the CÀOb onds of lignosulfonate and are resistant to sulfur poisoning.…”