WO₃ dehydration and phase transition as the catalytic driver of hydrogen production by non-calcinated WO₃

In this study, WO₃ (trioxide tungsten) was investigated as a catalyst for water reduction by NaBH₄ in basic conditions, which are not typical for NaBH₄ reduction processes. The results indicate that the structure of the WO₃ phase strongly affects the catalytic process. The uncalcinated WO_3, ncWO₃, which contains primarily tungstite with traces of hydro-tungstite is the only WO₃ form that acts as an effective catalyst. A cubic WO₃ is formed or exposed during the reduction process. Hydrogen production increases during reaction cycles; an interesting and important result. Plausible mechanisms of the catalytic process observed are outlined. The results have far-reaching effects that should be further investigated in other systems, such as the phase structures acting as a catalyst for treating toxic organic compounds.