Phase transition of SiC support induces dispersed Na₂WO₄ catalysts for CH₃Cl-to-C₂H₃Cl conversion

The development of efficient CH₃Cl-to-C₂H₃Cl catalysts remains challenging due to the poor dispersion of Na₂WO₄ at high loadings, which limits catalytic performance. This study addresses this issue by employing silicon carbide (SiC) as a support, which undergoes an in situ phase transformation to α-cristobalite during calcination, effectively enhancing Na₂WO₄ dispersion even at 35 wt% loading. The resulting catalyst achieved a vinyl chloride selectivity of 35.1% and a yield of 31.4% at 700 °C, significantly outperforming conventional Na₂WO₄/SiO₂ catalysts synthesized with α-cristobalite. These findings highlight the importance of support-mediated phase transformations in designing high-performance MCTV catalysts, offering a sustainable pathway for VCM production.