The LSV measurements were conducted using an Ag/AgCl reference electrode in 1 M H2SO4, with a Pt counter electrode placed behind a frit to prevent oxygen entry, but still in the same electrolyte solution. The potential range applied was from 0.2 to -0.55 V vs RHE (against RHE) for [Mo3S4] 4+ , and from 0.2 to -0.35 V vs RHE for [Mo3S13] 2-, with a scan rate of 0.5 mV/s. To stabilize the redox potential in the solution, hydrogen was bubbled electrochemically using two Pt wires connected to a second potentiostat. The Pt electrode generating oxygen was also behind a frit but remained in the same electrolyte solution. For the Tafel plot analysis, the applied potential was IR drop corrected using the formula: IR drop corrected potential = applied voltage -voltage drop, where the voltage drop was calculated by multiplying the current by the series resistance.