Selective Aerobic Oxidation of Lactate to Pyruvate Catalyzed by Vanadium‐Nitrogen‐Doped Carbon Nanosheets

Abstract

The catalytic oxidative dehydrogenation of lactates with molecular oxygen is a promising yet challenging route for producing high‐value pyruvates from biomass. Here we report a simple synthetic strategy for preparing nitrogen‐doped carbon nanosheets (NCNs) starting from two abundant precursors, cheap melamine and glucose, and using a simple thermal‐annealing process. The resulting NCNs feature numerous edges and holes for anchoring vanadium oxides (V‐NCNs). This creates cooperative catalytic sites that boost the catalytic oxidation of ethyl lactate to ethyl pyruvate. Additionally, we systematically studied the surface nitrogen species of NCNs by varying the pyrolysis temperature, and found that the active pyridinic N‐oxide species formed in a high thermal‐annealing treatment, acting synergistically with vanadium active sites in converting ethyl lactate with oxygen into ethyl pyruvate under mild conditions.

Efficient Aerobic Oxidation of Ethyl Lactate to Ethyl Pyruvate over V2O5/g-C3N4 Catalysts

“…The TiO 2 -supported vanadia catalyst calcined at 300 °C is also found to be more active as compared with the one calcined at 550 °C. The above results indicate that a low calcination temperature may account for the excellent activity of 13V 2 O 5 /g-C 3 N 4 , higher than that of the similar vanadium–nitrogen-doped carbon nanosheets prepared at 400 °C …”

“…12 The pyridinic N-oxide species in the catalyst was found to act synergistically with vanadium active sites in converting ethyl lactate with oxygen. 12 Mesoporous vanadia−titania was also efficient and recyclable in the conversion of ethyl lactate to ethyl pyruvate. 13 The V 4+ − O−Ti bonds were thought to play a key role in the reaction.…”

“…Supported vanadia was found to be more active when adding pyridine-type additives, through complexation of this additive to the substrate, followed by the oxidation on V active site . Based on that, vanadium–nitrogen-doped carbon nanosheets were prepared, which can convert ethyl lactate with oxygen into ethyl pyruvate under mild conditions, although auxiliary reagent needed to be added to suppress the occurrence of side reactions . The pyridinic N-oxide species in the catalyst was found to act synergistically with vanadium active sites in converting ethyl lactate with oxygen .…”

“…Based on that, vanadium–nitrogen-doped carbon nanosheets were prepared, which can convert ethyl lactate with oxygen into ethyl pyruvate under mild conditions, although auxiliary reagent needed to be added to suppress the occurrence of side reactions . The pyridinic N-oxide species in the catalyst was found to act synergistically with vanadium active sites in converting ethyl lactate with oxygen . Mesoporous vanadia–titania was also efficient and recyclable in the conversion of ethyl lactate to ethyl pyruvate .…”

One-pot conversion of dihydroxyacetone into ethyl lactate by Zr-based catalysts

“…Moreover, it can also be employed as a green precursor for the synthesis of other value-added chemicals. 4,5 Currently, EL is produced predominantly via esterication of lactic acid and ethanol catalyzed by H 2 SO 4 (ref. 6) and lipase.…”