Chlorella-derived porous heteroatom-doped carbons as robust catalysts for oxygen reduction reaction in direct glucose alkaline fuel cell

Abstract High cost and low efficiency of cathode catalyst as well as the sluggish oxygen reduction reaction (ORR) remain the main obstacles to the practical application of direct glucose alkaline fuel cells (DGAFCs). Herein, sponge-like porous carbons fortified with transition metal, nitrogen, and phosphorus (denoted by M-N/P C) were synthesized for the first time from highly available algal biomass of chlorella. The results showed that all the M(Fe,Co,Cu) N/P C catalysts exhibited excellent electrocatalytic performance for ORR. Especially, Fe N/P C obtained a half wave potential of 0.852 V (vs RHE) and a limiting current density of 4.4 mA cm −2 , which are comparable to those of commercial 10% Pt/C catalyst (E 1/2  = 0.815 V, J d  = 4.4 mA cm −2 ). In addition, Fe N/P C presents outstanding long-term stability and methanol resistance. A simple direct glucose fuel cell was assembled to further evaluate the catalytic ability of Fe N/P C. The fuel cell equipped with a Fe N/P C cathode achieved a peak power density of 30.53 W · m − 2 under ambient condition, which is superior to that with a 10% Pt/C cathode. This investigation provides a readily achievable route based on function-oriented fortification towards development of cost efficient ORR catalysts for AFCs.