Mo₂C/Graphene Nanocomposite As a Hydrodeoxygenation Catalyst for the Production of Diesel Range Hydrocarbons

Abstract

Carbon-supported Mo 2 C nanoparticles were synthesized and used as catalysts for the deoxygenation of oleic acid and soybean oil to produce diesel-range hydrocarbons. Various carbon materials, such as reduced graphene oxide (RGO), glassy spherical carbon (SC), activated carbon (AC), and mesoporous carbon (MC), were used as supports to determine the effects of RGO in the deoxygenation reactions. The effects of the flow rate, Mo content of the catalyst, and the structure of the carbon support on the conversion and product selectivity were investigated. The morphology analysis revealed that Mo 2 C nanoparticles were well-dispersed onto the RGO (Mo 2 C/RGO). Under moderate reaction condition (T = 350 °C, P = 5.0 MPa, H 2 /oil ratio = 4.5, LHSV = 2 h −1 ), oleic acid was efficiently deoxygenated using the Mo 2 C/RGO catalyst, which produced hydrocarbons with ≥85% yield and ≥90% hydrocarbon selectivity. This value was much higher than those obtained using the Mo 2 C/SC, Mo 2 C/AC, and Mo 2 C/MC catalysts (yields = 18.5−50.3%) under identical conditions. The higher catalytic activity of the RGO-supported catalyst originated from its large pore size, which facilitated transport of the reactants, and uniform deposition of the Mo 2 C nanoparticles on the RGO surface. Even over a short contact time (LHSV = 8 h −1 ) and using natural triglyceride as a reactant, the Mo 2 C/RGO catalyst exhibited ≥40% yield of hydrocarbons, whereas a commercial CoMoS x /Al 2 O 3 catalyst produced ≤10% yield under identical conditions. The Mo 2 C/RGO catalyst was highly selective toward C−O bond scission in the hydroxyl group, which produced water and hydrocarbons without truncating the carbon skeleton of the starting material. Mo 2 C/RGO exhibited a prolonged catalyst lifetime for the deoxygenation of soybean oil (13% decrease in conversion after 6 h), compared with the commercial CoMoS/Al 2 O 3 catalyst (42% decrease).

Supercritical Fluid‐Facilitated Exfoliation and Processing of 2D Materials

“…Sasikala and co-workers [17] have recently discussed supercritical fluid applications of graphene in conductive films [128,133] and field effect transistors, batteries, capacitors, solar cells, fuel cells, biological and environmental applications, sensors, catalysis (an Mo 2 C/rGO material obtaining hydrocarbons from glycerides), [193] and microwave absorption devices. Catalysis and energy account for a large majority of these applications and analytical applications such as imaging and sensors represent another primary focus.…”

“…[3,4] By using SCFs, the surfaces of graphene, rGO, or GO have been decorated with a variety of metal (such as Pt, [105,195] Ru, [105] Pd, [97,100,102,197] Ag, [84,198,216,217] Au, [100] Fe, [100] Ni, [100,105] PtRu, [199] PtFe, [107] and PtFeCo [200] ), metal oxide (such as ZnO, [99,101,218] Co 3 O 4 , [96] TiO 2 , [201,202,219] MoO 2 , [193] MnO 2 , [209] Al 2 O 3 , [215] and SnO 2 , [205] ), and metal sulfide (such as CdS [103] ) NPs with tunable sizes, loadings, and compositions. [3,4] By using SCFs, the surfaces of graphene, rGO, or GO have been decorated with a variety of metal (such as Pt, [105,195] Ru, [105] Pd, [97,100,102,197] Ag, [84,198,216,217] Au, …”

“…[193] This composite could be used as a catalyst for oleic acid deoxygenation to produce hydrocarbons with ≥85% yield and ≥90% hydrocarbon selectivity. [193] This composite could be used as a catalyst for oleic acid deoxygenation to produce hydrocarbons with ≥85% yield and ≥90% hydrocarbon selectivity.…”

“…Catalysis and energy account for a large majority of these applications and analytical applications such as imaging and sensors represent another primary focus. Sasikala and co‐workers have recently discussed supercritical fluid applications of graphene in conductive films and field effect transistors, batteries, capacitors, solar cells, fuel cells, biological and environmental applications, sensors, catalysis (an Mo 2 C/rGO material obtaining hydrocarbons from glycerides), and microwave absorption devices. A novel heterostructured material composed of graphene nanosheets encapsulated with MoS 2 nanosheets is a noteworthy advance in superhydrophobicity .…”

Effective Hydrodeoxygenation of Stearic Acid and Cyperus Esculentus Oil into Liquid Alkanes over Nitrogen‐Modified Carbon Nanotube‐Supported Ruthenium Catalysts

“…Noble metals such as Pt, Pd, and Rh‐based catalysts and some other nickel catalyst systems such as Metal oxides (Al 2 O 3 and mesoporous silica nanoparticles), zeolites (such as ZSM‐5, SAPO‐11, MCM‐41, and HY) and carbon‐supported nickel catalysts, zeolites‐supported NiMo catalysts, Ni−Al layered double hydroxide catalyst and Al‐SBA‐15‐supported Ni‐based transition metal carbide catalysts have already been reported. Moreover, tungsten and molybdenum carbide catalysts are reported to be capable of catalyzing the conversion of fatty acids and plant oil to liquid alkanes at 350 °C . The HDO of plant oil over metal oxides‐supported iron and cobalt catalysts have also been investigated recently.…”