Supplying global energy demand with CO2-free technologies is becoming feasible thanks to the rising affordability of renewable resources. Hydrogen is a promising vector in the decarbonization of energy systems, but more efficient and scalable synthesis is required to enable its widespread deployment. Here we report contactless H2 production via water electrolysis mediated by the microwavetriggered redox activation of solid-state ionic materials at low temperatures (<250 ºC). Water was reduced via reaction with non-equilibrium gadolinium-doped CeO2 that was previously in situ electrochemically deoxygenated by the sole application of microwaves. The microwave-driven reduction was identified by an instantaneous electrical conductivity rise and O2 release. This process was cyclable, whereas H2 yield and energy efficiency were material-and power-dependent. Deoxygenation of low-energy molecules (H2O or CO2) led to the formation of energy carriers and enabled CH4 production when integrated with a Sabatier reactor. This method could be extended to other reactions such as intensified hydrocarbons synthesis or oxidation.Sustainability of industry, transportation and energy management will rely on CO2-free technologies and renewable electricity, which are boosted by the rising affordability of photovoltaic solar and wind turbine parks. The electrification of industry and transport will strongly contribute to limiting greenhouse gas emissions 1,2 by using CO2-neutral energy carriers or chemical raw materials; however, the intermittent nature of renewables