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

New composite cathodes for proton conducting solid oxide fuel cells (PC-SOFCs) based on the novel La 5.5 WO 12Àd (LWO) electrolyte have been developed. First the applicability of LWO as a protonic electrolyte has been proved by recording the OCV in a Pt/LWO/Pt cell as a function of the temperature, matching the expected Nernst voltage. In order to improve the electrode performance on LWO PCSOFCs, composite cathodes have been prepared by mixing the La 0.8 Sr 0.2 MnO 3Àd (LSM) electronic phase with the LWO protonic phase. The ceramic-ceramic (cer-cer) composites have been electrochemically studied as cathodes on LWO dense electrolytes in symmetrical cells. Different ratios of both phases and two different electrode sintering temperatures (1050 and 1150 C) have been studied. Electrochemical impedance spectroscopy (EIS) analysis has been carried out in the temperature range 700-900 C under moist (2.5% H 2 O) atmospheres. Different oxygen partial pressures (pO 2 ) have been employed in order to characterize the processes (surface reaction and charge transport) taking place at the composite cathode. A substantial improvement in the cathode performance has been attained by the addition of the LWO protonic phase into the LSM electronic material. From the electrochemical analysis it can be inferred that electrode enhancement is principally ascribed to the increase in the three-phase-boundary length, which enables electrochemical reactions to occur along the thickness of the electrode.

Redox stability and electrochemical study of nickel doped chromites as anodes for H-2/CH4-fueled solid oxide fuel cells. Applied Catalysis B Environmental. 115:346-356.