Acid-modified Cu–Ce/HZSM-5 adsorbent removes trace phosphorus impurities from recycled hydrogen during polysilicon production†

Abstract

In this study, an acid-modified Cu–Ce/HZSM-5 bimetallic adsorbent was developed for the removal of trace PH₃ impurities from simulated recycled hydrogen in a chemical vapor deposition furnace for polysilicon production. A systematic examination was subsequently conducted to examine the effects of acidic substance type and concentration, and the addition of Ce on the adsorbent's ability to remove PH₃. The results showed that the adsorbent, when treated with 13% HNO₃ and an appropriate level of Ce (n_Ce : n_Cu = 1 : 40), exhibited superior adsorption performance, achieving a PH₃ breakthrough adsorption capacity of 135.2 mg g⁻¹. After three regeneration cycles, the sorbent achieved optimal performance. Further investigation indicated that the improved efficiency of this sorbent in removing PH₃ was primarily due to the formation of Cu₂(OH)₃NO₃, an increase in microporous volume, the enhanced distribution of metallic oxides, a higher quantity of reactive oxygen species on the surface, an increased concentration of acidic sites, and the exposure of additional reactive species (Cu₂(OH)₃NO₃, CuO). Moreover, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterization indicated that the deactivation of the adsorbent was mainly caused by the continuous consumption of Cu₂(OH)₃NO₃ and CuO, along with the accumulation of reaction products (P₂O₅, Cu₃P, Cu (PO₃)₂, and Cu₂P₂O₇) on the adsorbent surface.