Abstract:
The increasing global energy demand has necessitated a lookout for newer renewable
sources of energy that could replace or decrease the dependency of non-renewable
sources i.e. fossil fuel. Hydrogen can be used as fuel and can be produced in various
ways and one of the most effective means is by electrochemical water splitting.
Hydrogen and oxygen are produced at the cathodic and anodic half-cells of the
electrolyzer, respectively. However, due to the sluggish kinetics for the oxygen evolution
reaction, the overall cost-effectiveness of the system decreases significantly. This could
be overcome by using glycerol oxidation as the anodic half-cell reaction in the
electrolyzer having a lower theoretical oxidation potential than water, cogenerating
value-added products alongside. In this report, Co-based ZIF-67 (cobalt-based zeolitic
imidazolate framework) a sub-category of metal-organic framework (MOF) has been
pyrolyzed and used as an electrocatalyst for the glycerol oxidation reaction (GOR)
where the ZIF is acting as a self-sacrificial template for a nitrogen-doped carbon matrix
with metal nanoparticles dispersed within it. Morphological studies were carried out for
the catalyst using techniques like SEM, TEM and PXRD. Different electrochemical cell
setups like a rotating disk, H-cell and flow-through cells were used to investigate the
activity and stability of the catalyst. Product selectivity for the catalyst was examined
using techniques like HPLC, NMR and in-situ IR. Different products could be identified
like formic acid, glyceric acid and carbonate with formic acid being the major product.
Glyceric acid was also formed in substantial amounts.
