Copper loaded on sol-gel-derived alumina adsorbents for phosphine removal

The hydride gas of phosphine (PH3) is commonly used for semiconductor and optoelectronic industries. The local scrubbers must immediately abate it because of its high toxicity. In this study, copper (Cu) loaded on the sol-gel-derived γ-alumina (Al₂O₃) adsorbents are prepared and tested to investigate the possibility of PH₃ removal and sorbent regeneration. Test results showed that during the breakthrough time of over 99% PH₃ removal efficiency, the maximum adsorption capacity of Cu loaded on the sol-gel-derived γ-Al₂O₃ adsorbent is 18 mg-PH₃/g-adsorbent. This is much higher than that of Cu loaded on the commercial γ-Al₂O₃ adsorbent - 8.6 mg-PH ₃/g-adsorbent. The high specific surface area, narrow pore size distribution, and well dispersion of Cu loaded on the sol-gel-derived γ-Al₂O₃ could be the reasons for its high PH ₃ adsorption capacity. The regeneration test shows that Cu loaded on the sol-gel-derived γ-Al₂O₃ adsorbent can be regenerated after a simple air purging procedure. The cumulative adsorption capacity for five regeneration cycles is 65 mg-PH₃/g-adsorbent, which is approximately double that of the Cu/zeolite adsorbent demonstrated in the literature.