An overview of new approaches to deep desulfurization for ultra-clean gasoline, diesel fuel and jet fuel

Chemicals and materials from coal in the 21st century

Organic reactions catalyzed over solid acids

The adsorption of molecules on metal nanoparticles can be sterically controlled through the use of zeolite crystals, which enhances the product selectivity in hydrogenations of reactants with more than one reducible group. Key to this success was the fixation of Pd nanoparticles inside Beta zeolite crystals to form a defined structure (Pd@Beta). In the hydrogenation of substituted nitroarenes with multiple reducible groups as a model reaction, the Pd@Beta catalyst exhibited superior selectivity for hydrogenation of the nitro group, outperforming both conventional Pd nanoparticles supported on zeolite crystals and a commercial Pd/C catalyst. The extraordinary selectivity of Pd@Beta was attributed to the sterically selective adsorption of the nitroarenes on the Pd nanoparticles controlled by the zeolite micropores, as elucidated by competitive adsorption and adsorbate displacement tests. Importantly, this strategy is general and was extended to the synthesis of selective Pt and Ru catalysts by fixation inside Beta and mordenite zeolites.

A Pd@Zeolite Catalyst for Nitroarene Hydrogenation with High Product Selectivity by Sterically Controlled Adsorption in the Zeolite Micropores

Hydrogenation of Aromatics in Diesel Fuels on Pt/MCM-41 Catalysts☆

Per-hydrogenation of naphthalene produces both cis-decalin (c-DeHN) and trans-decalin (t-DcHN). Huang and Kang reported the rate data shown in Scheme 1 for this reaction catalyzed by Pt/Al{sub 2}O{sub 3}. Isomerization of c-DeHN was treated as irreversible, and it was assumed that dehydrogenation of DeHN could be neglected. We have found it possible to achieve high selectivity for one DeHN isomer by appropriate catalyst selection. For example, PYHY gives 100% naphthalene conversion to decalins with 80% selectivity for c-DeHN. There numerous potential industrial applications for c-DeHN; such as, the production of sebacic acid which can be used in the manufacture of Nylon 6, 10 and softeners. Conversely, catalysts that promote the thermodynamically favored c-DeHN to t-DeHN isomerization can be made to give nearly 96% t-DeHN. This reaction can be used in fuel upgrading applications, to increase the thermal stability of the fuel.

Grainne Bowers

Papers

Shape-selective hydrogenation of naphthalene over zeolite-supported Pt and Pd catalysts

Shape-selective hydrogenation of naphthalene over zeolite-supported Pt and Pd catalysts