Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Commissariat a L'energie Atomique

King Fahd University of Petroleum and Minerals

Frederic Schuster

Zain Hassan Yamani

Syed Ahmed Ali

Patrick David

Nouar Tabet

Yann Leconte

Axelle Quinsac

Thierry Piquero

Stephanie Anderbouhr

Elisabeth Blanquet

Gerald Theret

Julien Martegoutte

A particulate composite ceramic material may include: particles of at least one first ultra-high-temperature ceramic 'UHTC,' the outer surface of the particles being at least partially covered by a porous layer made of at least one second UHTC in amorphous form; and the particles defining a space therebetween; optionally, porous clusters of the at least one second ultra-high-temperature ceramic in amorphous form, distributed in said space; a dense matrix and at least one third UHTC in crystallized form at least partially filling the space; optionally, a dense coating made of at least the third UHTC in crystallized form, covering the outer surface of the matrix, the matrix and the coating representing 5% to 90% by mass with respect to the total mass of the material. A part may include such a particulate ceramic composite material.

Particulate composite ceramic material, part comprising said material, and method for the preparation of said part

A process for producing an unsupported molybdenum sulfide nanocatalyst comprising atomizing a molybdenum oxide solution to form a molybdenum oxide aerosol, pyrolyzing the molybdenum oxide aerosol with a laser beam to form the unsupported molybdenum-based nanocatalyst, and pre-sulfiding at least a portion of the unsupported molybdenum-based nanocatalyst to form an unsupported molybdenum sulfide nanocatalyst, wherein the unsupported molybdenum-based nanocatalyst, the unsupported molybdenum sulfide catalyst or both are in the form of nanoparticles with a diameter of 1-10 nm and in a distorted rutile crystalline structure. A method of selective deep hydrodesulfurization whereby a hydrocarbon feedstock having at least one sulfur-containing component and at least one hydrocarbon is contacted with the unsupported molybdenum sulfide nanocatalyst.

Process for selective deep hydrodesulfurization of a hydrocarbon feedstock using an unsupported nanocatalyst made by laser pyrolysis

The invention relates to a process for the preparation of a multilayer coating, comprising a stack, on a substrate, of several layers chosen from among layers constituting by TiN and layers constituted by (Ti,Al)N, also known as Ti.sub.1-x Al.sub.x N, the entire coating being produced in a single, continuous operation by thermal chemical vapour deposition (CVD) from a gaseous mixture comprising a reducing gas, such as ammonia or nitrogen, hydrogen and titanium and optionally aluminium chlorides, the nature and/or composition of each deposited layer being instantaneously adjusted by modifying the reducing gas to hydrogen molar ratio in the gaseous mixture. The invention also relates to multilayer coatings comprising (Ti,Al)N layers of variable compositions and in particular with composition gradient. Application to wear-resistant or abrasion-proof coatings having a resistance to oxidation and corrosion, particularly at high temperatures.

Process for the preparation by chemical vapor deposition (CVD) of a

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Paris, France

Frederic Schuster