<p>Metals and alloy production contribute ~ 10% of the global greenhouse gas emissions, largely due to the carbon-based reduction of mineral oxides. This significant environmental impact has driven a global search for carbon-free alternatives to conventional reduction processes. Among the emerging technologies, hydrogen plasma-based reduction processes are promising candidates. Here, we assess the applicable range of dissociative metal oxide reduction with argon-hydrogen plasmas through experiments, conducted in a microwave plasma reactor with a residence time on the order of 10 ms, and thermodynamic calculations. Metal oxides with increasing thermodynamic resistance to reduction by hydrogen are explored: NiO, Fe₃O₄, ZnO, Cr₂O₃, MnO₂, and SiO₂. Experiments reveal the successful reduction of NiO, Fe₃O₄, and ZnO to their respective metals. Cr₂O₃ is found to reduce to a mix of metallic Cr, Cr₂O₃, and an unidentified CrO_x phase. MnO₂ and SiO₂ are only partially reduced to MnO and SiO_x&lt;2 with embedded Si nanocrystals, respectively. Thermodynamic calculations, along with the experimental results, elucidate the respective pathways for dissociative reduction and the key steps limiting the process.</p>