Noble metal catalysts and processes for reforming of methane and other hydrocarbons

A CO2-steam reforming process comprising contacting a stream of a gaseous mixture comprising one or more hydrocarbons including methane, together with CO2 and H2O as oxidants, with a catalyst to produce a stream of a synthesis gas product, the process further comprising:

• determining a molar H2:CO ratio of the synthesis gas product and, based on the molar H2:CO ratio, adjusting a molar H2O:CO2 ratio of the gaseous mixture toward a target molar H2:CO ratio of the synthesis gas product,
• wherein the contacting is performed under reforming conditions including a weight hourly space velocity (WHSV), based on a weight flow of the gaseous mixture divided by a weight of the catalyst, from about 0.1 hr−1 to about 2.5 hr−1,
• wherein the catalyst comprises platinum (Pt) in an amount from about 0.3 wt-% to about 3 wt-% on a solid support comprising at least about 80 wt-% of cerium oxide, in combination with one or more other metal oxides selected from the group consisting of aluminum oxide, silicon oxide, titanium oxide, magnesium oxide, and strontium oxide, and
• wherein, under said reforming conditions, a conversion of the methane is at least about 75% by reaction with CO2 and H2O as the oxidants.

A CO2-steam reforming process comprising contacting a gaseous mixture comprising one or more hydrocarbons including methane, together with CO2 and H2O as oxidants, with a catalyst to produce a stream of a synthesis gas product having a molar H2:CO ratio of at least about 1.5:1,

• wherein the catalyst comprises platinum (Pt) in an amount from about 0.3 wt-% to about 3 wt-% on a solid support comprising at least about 80 wt-% of cerium oxide, in combination with one or more other metal oxides, and
• wherein, under said reforming conditions, a conversion of the methane is at least about 75% by reaction with CO2 and H2O as the oxidants,
• wherein said molar H2:CO ratio and said conversion of methane are maintained for an operating period of at least 500 hours of continuous or discontinuous operation, without undergoing regeneration over said operating period, and
• wherein said CO2-steam reforming process is endothermic.