One-step synthesis of methanol and hydrogen from methane and water using non-thermal plasma and Cu-Mordenite catalyst

In this study, the copper-mordenite zeolite (Cu-MOR) and non-thermal plasma were used to produce methanol and hydrogen from methane and water at low temperature (120 degrees C) without CO2 formation. Energy efficiency for methanol and hydrogen were 68.8 mmol center dot kJ(-1) and 562.3 mmol center dot kJ(-1), respectively, and the selectivity of meth-anol in liquid products reached 86%. The reaction mechanism likely involves methane being excited to methyl (center dot CH3) and hydrogen radicals (center dot H) under DBD plasma conditions, which can then adsorb on the catalyst surface at the Cu-2-(mu-O)(2+) active sites, accompanied by water co-adsorption to facilitate formation and desorption of methanol. XPS analysis showed that with the prolongation of reaction time, Cu-2-(mu-O)(2+) was reduced to Cu+ and Cu(II) hydroxide, and the catalyst had carbon deposition, resulting in the decrease of catalytic activity. It is also worth noting that in an oxygen atmosphere, Cu-2-(mu-O)(2+) regenerates rapidly and eliminates catalyst carbon deposits. Trace oxygen was introduced into the reactor, and the reaction was carried out for 30 h, and the catalytic activity did not decrease.