Standard Gibbs energy of formation of ZrMo2O8

The oxide ZrMo2O8 is the only ternary compound existing in the Zr-Mo-O system as reported in the literature. To determine the standard Gibbs energy of formation of ZrMo2O8 (hexagonal) from the constituent binary oxides ZrO2(s) and MoO3(s), the emf of the galvanic cell Pt, ZrO2, MoO2, ZrMo2O8vertical stroke15 wt% Y2O3 stabilized ZrO2vertical strokeair (PO2=0.21 atm), Pt has been studied over the range 986 to 1206 K and emf has been determined to be (EI±1.56) (mV)=772.42-0.29777T(K). Using the literature data, ΔGfo of MoO2(s) and MoO3(s), the ΔGof,ox(ZrMo2O8) has been found to be ΔGof,ox±13.2 (kJ/mol)=25.73-0.06157T(K). (orig.)