11Electroreduction of Carbon Dioxide
constitute the reverse of fuel combustion, as they remove oxygen from CO
2
and H
2
O [42].
Several processes have been developed for CO
2
xation; however, many
of them are expensive, since they either require ultra-high-purity CO
2
or
are energy intensive. In addition, many of the chemical methods show
low product selectivity. Such limitations can be overcome by applying
electrochemical procedures, which increase reaction pathway selectivity
and reduce costs, as they allow direct control of the surface free energy
by setting the electrode potential [9]. Feasible routes towards synthetic
fuels are either from direct electroreduction of CO
2
[36] or indirect pro-
cedures, where H
2
O and CO
2
are electrolysed in solid ...