Direct Electrocatalytic Oxidation of Hydrocarbons

In principle, SOFCs can operate on natural gas or other hydrocarbon fuels without the addition of any oxidant to the fuel, instead directly oxidising the hydrocarbon fuel on the anode using the oxide ions which have passed through the solid electrolyte from the cathode [65-71], The hydrocarbon can either be partially oxidised by the oxide ions to carbon monoxide and hydrogen (Eqs. (15) and (16)), or fully oxidised to CO2 and water (Eqs. (17) and (18)), or undergo a mixture of partial and total oxidation  

The major problem with direct electrocatalytic oxidation of the hydrocarbon fuel at the anode is the marked tendency towards carbon deposition via hydrocarbon decomposition (Eqs. (1) and (2)). It is extremely difficult to avoid carbon deposition in the absence of a co-fed oxidant. However, some recent studies have reported anodes which show considerable promise for the direct electrocatalytic oxidation of hydrocarbons [29,68,69]. The conditions under which these anodes can be used may present problems for their widespread application, whilst their long-term durability with respect to carbon deposition must be established. Electrically conducting oxides have also been proposed in recent years as having potential for use as anodes for the direct electrocatalytic oxidation of hydrocarbons [67.70,74]. 

The concept of using an SOFC as an electrocatalytic reactor for chemical cogeneration has attracted much interest [72,73], offering the possibility of 

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