Compositions including oxycarbide-based nanorods and/or carbide-based nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including oxycarbide-based nanorods and/or carbide based nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided. The fluid phase catalytic reactions catalyzed include hydrogenation, hydrodesulfurisation, hydrodenitrogenation, hydrodemetallisation, hydrodeoxigenation, hydrodearomatization, dehydrogenation, hydrogenolysis, isomerization, alkylation, dealkylation and transalkylation.

A ceramics composite member includes a structure in which a first ceramic member and a second ceramic member are integrated with a joint portion. The joint portion has a texture in which a silicon phase having an average diameter of 0.05 µm or more and 10 µm or less is continuously provided in a network form in interstices of silicon carbide particles having an average particle diameter of 0.1 µm or more and 0.1 mm or less.