The catalyst for a hydrogenation reaction according to an exemplary embodiment of the present application comprises: a porous carrier; a catalytic component supported on the porous carrier; and a polymer provided on at least a part of the surfaces of the porous carrier and the catalytic component and comprising the repeating unit represented by Chemical Formula 1.

Catalyst comprising nickel and copper, in a proportion of 1% to 50% by weight of nickel element relative to the total weight of the catalyst, in a proportion of 0.5% to 15% by weight of copper element relative to the total weight of the catalyst, and an alumina support, said catalyst being characterized in that: the mole ratio between nickel and copper is between 0.5 and 5 mol/mol; at least one portion of the nickel and copper is in the form of a nickel-copper alloy; the nickel content in the nickel-copper alloy is between 0.5% and 15% by weight of nickel element relative to the total weight of the catalyst, the size of the nickel particles in the catalyst is less than 7 nm.

Catalyst comprising nickel and copper, in a proportion of 1% to 50% by weight of nickel element relative to the total weight of the catalyst, in a proportion of 0.5% to 15% by weight of copper element relative to the total weight of the catalyst, and an alumina support, said catalyst being characterized in that: the mole ratio between nickel and copper is between 0.5 and 5 mol/mol; at least one portion of the nickel and copper is in the form of a nickel-copper alloy; the nickel content in the nickel-copper alloy is between 0.5% and 15% by weight of nickel element relative to the total weight of the catalyst, the size of the nickel particles in the catalyst is less than 7 nm.

Methods for the selective hydrogenation of acetylenic compounds in a product stream that includes isoprene. A method of selectively hydrogenating an acetylenic hydrocarbon in the presence of isoprene may include obtaining a hydrocarbon mixture comprising an acetylenic hydrocarbon, isoprene, and butadiene or cyclopentadiene, or both. If cyclopentadiene is present, the hydrocarbon mixture may comprise greater than 2 wt. % cyclopentadiene. The method may further include contacting the hydrocarbon mixture and hydrogen (H.sub.2) with a hydrogenation catalyst under reaction conditions that are more selective to the hydrogenation of the acetylenic hydrocarbon than the isoprene.

Catalyst comprising nickel and sulfur on an alumina support, said catalyst being characterized in that: the nickel is distributed both on a crust at the periphery of the support, and in the core of the support, the thickness of said crust being between 2% and 15% of the diameter of the catalyst; the nickel density ratio between the crust and the core is strictly greater than 3; said crust comprises more than 25% by weight of nickel element relative to the total weight of nickel contained in the catalyst, the size of the nickel particles in the catalyst, measured in oxide form, is between 7 and 25 nm.

Catalyst comprising nickel and sulfur on an alumina support, said catalyst being characterized in that: the nickel is distributed both on a crust at the periphery of the support, and in the core of the support, the thickness of said crust being between 2% and 15% of the diameter of the catalyst; the nickel density ratio between the crust and the core is strictly greater than 3; said crust comprises more than 25% by weight of nickel element relative to the total weight of nickel contained in the catalyst, the size of the nickel particles in the catalyst, measured in oxide form, is between 7 and 25 nm.

Disclosed are processes for converting an alkyne to an olefin comprising feeding a molecular-oxygen-containing gas stream into a converting zone of an alkyne converter along with an alkyn-containing feed mixture comprising hydrocarbons and molecular hydrogen to contact the converting catalyst. The converting catalyst can be regenerated online as a result.

Disclosed are processes for converting an alkyne to an olefin comprising feeding a molecular-oxygen-containing gas stream into a converting zone of an alkyne converter along with an alkyn-containing feed mixture comprising hydrocarbons and molecular hydrogen to contact the converting catalyst. The converting catalyst can be regenerated online as a result.

Disclosed are processes for converting an alkyne to an olefin comprising feeding a molecular-oxygen-containing gas stream into a converting zone of an alkyne converter along with an alkyn-containing feed mixture comprising hydrocarbons and molecular hydrogen to contact the converting catalyst. The converting catalyst can be regenerated online as a result.

Disclosed herein are embodiments of aryl compounds and polymers thereof that are made using methods that do not require harsh conditions or expensive reagents. The methods disclosed herein utilize precursor compounds that can be polymerized to form polycyclic aromatic hydrocarbons and polymers, such as carbon-based polymers like nanostructures (e.g., graphene or graphene-like nanoribbons).