Experimental and theoretical investigation of the electronic, magnetic, and optical properties of a new oxyphosphate, Ni0.25Mn0.25TiO(PO4)

A Highly Efficient Nickel Phosphate Electrocatalyst for the Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

“…As shown in Figure 8, two broad weak peaks were observed at around 459 and 545 cm −1 , and a strong peak was observed at 735 cm −1 , corresponding to the vibration of the Ni−O bond over both Ni 3 (PO 4 ) 2 and Ni(OH) 2 in KOH solution without power supply. 17,18 After applying a potential of 1.464 V, two obvious peaks appeared at 475 and 557 cm −1 (Figure 8a), which are due to the presence of Ni−O bending and Ni−O stretching vibrations characteristic of nickel species with high valence, namely, Ni 3+ species. 19 It shows that the Ni 2+ is electro-oxidized to active nickel species with high valence/Ni 3+ species in KOH solution.…”

“…22 After applying a potential of 1.464 V, the peaks at 1110 and 1300 cm −1 disappeared and new bands appeared at 1219 and 1030 cm −1 , which correspond to the stretching vibration of the ringshaped P−O bond and P−OH bond, respectively. 17,23 It can be inferred that KOH reacted with the PO group in Ni 3 (PO 4 ) 2 to form P−OH and ring-shaped P−O species. Then, HMF was further added to the reaction solution; the above two O−H bonds shifted to 3375 and 1639 cm −1 , indicating that the OH − group is involved in the oxidation reaction.…”

“…Photocatalytic HMF-to-FDCA conversion requires moderately active species to achieve the selectivity toward FDCA instead of CO 2 . Also, the electrocatalytic process has the advantages of proceeding at ambient temperatures and pressures without the need for chemical oxidizing agents and with simultaneous H 2 production at lower overpotentials than that in a typical water electrolysis process by replacing the oxygen evolution reaction (OER) at the anode with HMF oxidation. , Moreover, the share of renewable energy sources such as solar and wind power in global electricity generation can lead to the cut of the electrochemical production process cost. So, electrochemical oxidation of HMF is a good alternative route to prepare FDCA economically.…”