Enhanced ORR kinetics and stability through synergy of Pt-Ni clustering and porous N-doped C/Ca aerogel support

•C/Ca aerogels possess high BET surface area and porous structure, enhancing catalyst performance.•Pt-Ni and pyridinic-N species provide additional active sites, facilitating ORR efficiency.•Pt25Ni75-C/Ca showed lower Tafel slopes and higher electrochemical activity than Pt/C.•Pt25Ni75-C/Ca retained over 90 % activity after 40,000 s testing, showing great stability. The oxygen reduction reaction (ORR) is fundamental in numerous electrochemical energy conversion technologies, necessitating efficient catalysts to enhance reaction kinetics and reduce precious metal usage. This study focuses strategic clustering of Pt-Ni on Calcium Oxide/activated carbon (C/Ca) aerogels. Electrochemical analyses confirmed that incorporating Ni into Pt matrices significantly enhanced ORR activities with Pt25Ni75-C/Ca composition emerged as optimum. A positive shift in half-wave potential (905 mV vs. RHE) and impressive mass activity (72.50 Ag−1 at 85 V) highlight the potential of this composite as a highly effective and stable ORR catalyst. Pt-C/Ca demonstrated performance fluctuation, while Pt25Ni75-C/Ca showed remarkable stability after 40,000 cycles. Furthermore, C/Ca aerogels exhibited a significantly increased BET surface area, and the presence of Pt-Ni/pyridinic-N species on its surface C/Ca aerogel provided supplementary active sites that facilitated the adsorption and reduction of O2 during ORR. [Display omitted]