Durable and renewable guanidine-grafted resin for heterogeneously catalytic cracking of chlorosilanes

The catalytic cracking of high-boiling chlorosilanes, such as Si 2 Cl 6 —common by-products in polysilicon production—into lower-boiling-point chlorosilanes is essential for their reuse. However, conventional liquid-phase amine catalysts suffer from limited durability and low economic viability due to deactivation caused by metal impurities such as Al 3+ and Ti 4+ . In this work, a novel solid-state guanidine-grafted Merrifield resin (G-M-resin) catalyst was successfully synthesized via nucleophilic substitution. Significantly, the newly developed G-M-resin catalyst exhibits excellent durability, high efficiency , and recyclability in the catalytic cracking of Si 2 Cl 6 . After five reaction cycles, the G-M-resin catalyst maintains high catalytic efficiency, with only a 9% loss in the presence of Al 3+ and a 23.6% loss with both Al 3+ and Ti 4+ . In contrast, a conventional organic amine catalyst suffered a 40.8% loss of activity under Al 3+ and was completely deactivated when both metal ions were present. The superior stability of the G-M-resin catalyst originates from the low binding energy between the grafted guanidine groups and the interfering metal ions (Ti 4+ and Al 3+ ), thereby effectively preserving the active sites from deactivation. Furthermore, the solid-state design of the G-M-resin catalyst facilitates its regeneration, allowing for full recovery of initial performance after reactivation. This addresses a key limitation associated with conventional liquid amine catalysts. This work presents a durable and regenerable solid catalyst for converting high-boiling chlorosilanes, offering a promising strategy for maintaining catalytic activity in challenging environments.