Catalytic Dual Inhibition Pathways in N- and S-Modified LDHs: Metal Hydroxide Layers Versus N/S Functional Groups for Catalytically Inhibiting Chlorobenzene Formation During Waste Incineration

This study investigates the dual catalytic inhibition mechanisms of chlorobenzene (CBz) formation during combustion using N- and S-modified layered double hydroxides (LDHs). The metal hydroxide layers in these LDHs primarily suppress lower-chlorinated CBzs (e.g., trichlorobenzene-dichlorobenzene) under inert conditions by inhibiting direct chlorination, achieving inhibition rates above 80%. In contrast, N/S functional groups, particularly thioacetamide, enhance catalytic inhibition efficiency under air, increasing it from 17.8% to 77.3% in the solid phase by controlling catalytic chlorination and limiting highly chlorinated CBzs (e.g., pentachlorobenzene–hexachlorobenzene). These findings highlight the complementary roles of metal hydroxide layers and N/S functional groups in reducing CBz formation, offering insights for developing efficient, multifunctional inhibitors for waste incineration pollution control. While promising, the scaling up of the application of LDH-based inhibitors may face challenges related to synthesis complexity and cost, requiring further research to provide a theoretical foundation for their large-scale application.