Anthony Garron

Low temperature hydrogenolysis of waxes to diesel range gasoline and light alkanes: Comparison of catalytic properties of group 4, 5 and 6 metal hydrides supported on silica–alumina

A series of metal hydrides (M = Zr, Hf, Ta, W) supported on silica–alumina were studied for the first time in hydrogenolysis of light alkanes in a continuous flow reactor. It was found that there is a difference in the reaction mechanism between d0metal hydrides of group 4 and d0 ↔ d2metal hydrides of group 5 and group 6. Furthermore, the potential application of these catalysts has been demonstrated by the transformation of Fischer–Tropsch wax in a reactive distillation set-up into typical gasoline and diesel molecules in high selectivity (up to 86 wt%). Current results show that the group 4 metal hydrides have a promising yield toward liquid fuels.

Improved direct production of 2,3-dimethylbutenes and 3,3-dimethylbutene from 2-methylpropene on tungsten hydride based catalysts

2-Methylpropene in the presence of W–H/Ni1%–Al2O3-(500) is transformed in high selectivity into a mixture of 2,3-dimethylbutenes (2,3-DMBs = DMB-1 and DMB-2) and neohexene. 2,3-DMBs arise from the unfavoured 2-methylpropene self-metathesis reaction whereas the neohexene originates from a cascade reaction: 2-methylpropene dimerisation followed by cross metathesis.

Direct thermocatalytic transformation of pine wood into low oxygenated biofuel

Direct catalytic conversion of pine wood under H2 into an organic liquid composed of saturated alkanes and aromatics has been achieved. The resulting organic liquids are easily isolated from the aqueous phase with a yield up to 30 wt%. Importantly, the oxygen content is about 3 wt% and has a higher heating value of 41 MJ kg−1 which is very close to standard diesel (44 MJ kg−1) used in automotive fuels. The multi-functional catalysts comprise well size controlled bimetallic nanoparticles (Cu–Ru) supported on heteropolyacid salts. The residual acidic proton of the heteropolyanion salt combined with bimetallic nanoparticles produced a multifunctional catalyst, featuring depolymerisation, deoxygenation and hydrogenation in a single batch reactor. Current results present an alternative approach to transform lignocellulosic biomass (oxygen content higher than 40 wt%) directly into an organic liquid (oxygen content less than 5 wt%) suitable as additives in biofuels.

Bifunctional Catalysts Based on Tungsten Hydrides Supported on Silicated Alumina for the Direct Production of 2,3-Dimethylbutenes and Neohexene from Isobutene

Well‐defined bifunctional supported catalysts that comprise tungsten hydride moieties and Brønsted acid sites were prepared successfully. The catalysts showed outstanding activities and selectivities toward the formation of high‐value‐added products, 2,3‐dimethylbutenes and 3,3‐dimethylbutene, through a combination of the metathesis and dimerization of isobutene. The relationship between the physicochemical properties of the catalysts and their activities and selectivities indicated that isobutene conversion increased from 4 to 95 % as a function of the silica content of the silicated alumina (obtained from Sasol). Nevertheless, the selectivity toward branched hexenes showed a volcano‐shaped curve that presented a maximum for the catalyst with 5 wt % silica. Therefore, the control of the support acidity by the silica loading on alumina resulted in an increase of the selectivity toward neohexene.

Impact of Surface Chemistry on Copper Deposition in Mesoporous Silicon

An easy, efficient, and safe process is developed to metallize mesoporous silicon (PSi) with Cu from the decomposition of a solution of mesitylcopper (CuMes) in an imidazolium-based ionic liquid (IL), [C1C4Im][NTf2]. The impregnation of a solution of CuMes in IL affords the deposition of metallic islands not only on the surface but also deep within the pores of a mesoporous Si layer with small pores below 10 nm. Therefore, this process is well suited to efficiently and completely metallize PSi layers. An in-depth mechanistic study shows that metal deposition is due to the reduction of CuMes by surface silane groups rather than by Si oxidation as observed in aqueous or water-containing media. This could open a new route to the chemical metallization of PSi by less-noble metals difficult to attain by a conventional displacement reaction.