In order to demonstrate the possibility of using WCG as fuel in high temperature carbon fuel cells, we assembled the cells comprised of CB and WCG. Expectedly, the overall cell performance of the carbon fuel cells improved with the increase in the operating temperature. WCG generally has higher operating voltages with increasing current density than the CB, as seen in Fig. 1. For instance, WCG-powered fuel cells exhibited a power density of 87.2 mW cm−2 at 900 °C, which is almost twice higher than CB-powered anodes (46.3 mW cm−2). In addition, the open circuit potential (OCP) of WCG is noticeably higher than that of CB, which could suggest that not only carbon electrochemical oxidation occurs in the WCG-powered cells but other oxidation reactions as well.