The present embodiments include systems and methods for converting ortho hydrogen to para hydrogen using, for example, a heat exchange wall that may be coated with a catalyst material.

A structured catalyst for catalyzing an endothermic reaction of a feed gas to convert it to a product gas is provided.

Array including a first and a second monolith of a structured catalyst for carrying out an endothermic reaction of a feed gas, wherein: a) the first and second monolith include a macroscopic structure of a first and second electrically conductive material; b) each of said first and second monoliths has a number of flow channels formed therein for conveying feed gas through the monoliths; c) the array includes at least a first and a second conductor electrically connected to said first and second monoliths, respectively, and to an electrical power supply, d) the first and second monolith are electrically connected by a monolith bridge; e) the array is configured to direct an electrical current to run from the first conductor through the first monolith to a second end, then through the bridge, and then through the second monolith to the second conductor.

A reactor, system, and method of converting methane non-oxidatively. A thermal catalytic reactor has a non-oxidative methane coupling (NMC) catalyst disposed on a first surface of a substrate. The NMC catalyst endothermically converts methane in a reaction zone on the catalyst side of the reactor to a product mixture. The reaction zone is heated by thermal conduction. The spatial temperature profile has a sharp increase and decrease that leads to selective control of the surface methane activation and gas phase reaction propagation. The reactor also has an inlet for introducing methane gas for contacting the NMC catalyst and an outlet for removing the product mixture. The heat source may generate the process heat chemically or electrically. Temperature profiles are controlled by zoning the combustion catalyst location or conductive heating element in the reactor.