Vanadium based battery is considered one of the most promising candidates to overcome the limitations of lithium ion battery in large-scale energy storage systems. However, the high manufacturing cost of the vanadium electrolyte has been hindered to commercialize. Although the catalytic production of vanadium electrolyte was reported, with an organic reducing agent such as formic acid is considered as a promising method, the continuous production of vanadium electrolyte is still difficult owing to the limited catalyst durability. Herein, we present the highly durable and active intermetallic Pt-alloyed catalysts, i.e., L1₂-Fe_0.25Pt_0.75/C and L1₂-Co_0.25Pt_0.75/C, for the catalytic production of V^3.5+ electrolyte. In the catalytic test of electrolyte production, the intermetallic L1₂-Fe_0.25Pt_0.75/C showed nearly 3 times higher activity than the commercial Pt/C catalyst. In the catalyst durability test, on the other hand, the intermetallic L1₂​-Co_0.25Pt_0.75/C showed only 3 % decrease of initial activity whereas the intermetallic L1₂-Fe_0.25Pt_0.75/C and commercial Pt/C exhibited ca. 9 % and ca. 20 % decrease of initial activity, respectively, for one hundred times continuous electrolyte production test. Among the catalysts tested, the intermetallic L1₂-Fe0.25Pt0.75/C showed the highest initial catalytic activity while the L1₂​-Co_0.25Pt_0.75/C exhibited the strongest catalyst durability. In terms of catalytic activity and stability, the intermetallic L1₂-Co_0.25Pt_0.75/C was found to be an efficient catalyst for the practical production of V^3.5+ electrolyte.