Graphene carbon black as catalyst support: The influences of iron phthalocyanine loading and carbon black additive amount on the power generation performance of direct glucose fuel cell

Fast accessibility of oxygen reduction reaction (ORR) species to a catalyst surface with the efficient utilization of every catalytic site plays a critical role in catalysis. Therefore, engineering of the structure and morphology of catalyst supports to both anchor and expose catalytic sites at three-phase-boundaries, accelerating the mass transport of reaction-species through the active sites, can be regarded as one of the most prospective methods to promote the efficient utilization of every catalytic site, giving prominent cell performance. Herein, two series of oxygen reduction reaction catalysts are prepared: reduced graphene oxides (rGO) with different loading amounts of iron phthalocyanine TFePc/rGO-X (X = 1,2,3,4 and 5); and TFePc/rGO-3 that is intercalated by different amounts of carbon black TFePc/rGO/CB-Y (Y = 1,2,3,4 and 5). The catalytic activities and stabilities of these catalysts were evaluated by cyclic voltammetry and linear sweep voltammetry. As expected, the 3D rGO/CB/rGO network is demonstrated as a singular catalyst-loading platform, with interlayer spacing that could be elaborately tuned via a simple carbon black intercalation. This enables ORR-species to be efficiently transported to each catalytic site. Besides, the optimal catalyst of TFePc/rGO/CB-3 exhibits more positive ORR peak potential than Pt/C catalyst. More significantly, in a practical cell, the cell performances were highly consistent with ORR active and the first-best cell performance of 0.86 mWcm(-2) in power density was achieved for TFePc/rGO/CB-3. This is mainly attributed to the synergistic effect of rGO and carbon black, as well as the pi-pi interaction between rGO and TFePc.

Automated summary

Efficient oxygen reduction reaction (ORR) species accessibility to catalyst surface is crucial for catalysis, and can be achieved by engineering the structure and morphology of catalyst supports. The 3D rGO/CB/rGO network, as a unique catalyst-loading platform, demonstrates efficient transport of ORR-species to each catalytic site, leading to significant improvements in cell performance. The synergistic effect of rGO and carbon black, as well as pi-pi interaction between rGO and TFePc, play important roles in achieving a high power density of 0.86 mWcm(-2) for TFePc/rGO/CB-3 in practical cells.