H2 production from formic acid over highly stable and efficient Cu-Fe-O spinel based photocatalysts under flow, visible-light and at room temperature conditions

Earth-Abundant-Based Photocatalysts for Efficient and Selective H2 Production through Reforming of Formic Acid under Visible Light

“…Synthesis of cuprospinel (Cu–Fe–O spinel): This sample, labeled Cu/Fe (1:3) in our previous work, was synthesized by the starch-assisted sol–gel autocombustion method. The desired amounts of iron­(III) nitrate and copper­(II) nitrate were dissolved in deionized water to obtain a homogeneous solution.…”

“…According to previous studies, this drawback of Cu 2 O-based catalysts can be overcome by the formation of a heterojunction with other semiconductors characterized by appropriate valence and conduction band edges alignment. , To date, such an approach allowed for significant enhancement of Cu 2 O activity in various photocatalytic processes by combination of copper oxide with selected wide band gap metal oxides (e.g., TiO 2 , CeO 2 , Nb 2 O 5 , etc.) as well as other materials that can be activated under visible light (e.g., CuO, Fe 2 O 3 , Cu–Fe–O spinel and Fe 3 O 4 , etc.). The majority of studies involving copper-containing composites for hydrogen production via formic acid dehydrogenation are focused on liquid-phase dehydrogenation.…”

“…Despite the high activity of the materials assigned to a synergetic effect between the residue of tetrahedrally coordinated Cu species and the spinel support, the selectivity of the reaction was relatively low (around 70%). 12 On the other hand, it was documented that Cu 2 O can catalyze selective transformation of FAc to H 2 and CO 2 without formation of CO as undesirable side product. 13 However, its efficiency in hydrogen production was found to be strongly limited because of a relatively fast recombination of photoexcited charge carriers (e − and h + ).…”

“…13,14 To date, such an approach allowed for significant enhancement of Cu 2 O activity in various photocatalytic processes by combination of copper oxide with selected wide band gap metal oxides (e.g., TiO 2 , 15 CeO 2 , 16 Nb 2 O 5 , 17 etc.) as well as other materials that can be activated under visible light (e.g., CuO, 18 Fe 2 O 3 , 19 Cu−Fe−O spinel 12 and Fe 3 O 4 , 20 etc.). The majority of studies involving copper-containing composites for hydrogen production via formic acid dehydrogenation are focused on liquid-phase dehydrogenation.…”

“…Very recently, we investigated a copper iron spinel (CuFe 2 O 4 )-based catalyst for formic acid dehydrogenation under visible light. Despite the high activity of the materials assigned to a synergetic effect between the residue of tetrahedrally coordinated Cu species and the spinel support, the selectivity of the reaction was relatively low (around 70%) . On the other hand, it was documented that Cu 2 O can catalyze selective transformation of FAc to H 2 and CO 2 without formation of CO as undesirable side product .…”