Copper Loaded on Sol-Gel-Derived Alumina Adsorbents for Phosphine Removal

Abstract

The hydride gas of phosphine (PH 3 ) 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-gelderived ␥-alumina (Al 2 O 3 ) adsorbents are prepared and tested to investigate the possibility of PH 3 removal and sorbent regeneration. Test results showed that during the breakthrough time of over 99% PH 3 removal efficiency, the maximum adsorption capacity of Cu loaded on the sol-gel-derived ␥-Al 2 O 3 adsorbent is 18 mg-PH 3 /gadsorbent. This is much higher than that of Cu loaded on the commercial ␥-Al 2 O 3 adsorbent-8.6 mg-PH 3 /gadsorbent. The high specific surface area, narrow pore size distribution, and well dispersion of Cu loaded on the sol-gel-derived ␥-Al 2 O 3 could be the reasons for its high PH 3 adsorption capacity. The regeneration test shows that Cu loaded on the sol-gel-derived ␥-Al 2 O 3 adsorbent can be regenerated after a simple air purging procedure. The cumulative adsorption capacity for five regeneration cycles is 65 mg-PH 3 /g-adsorbent, which is approximately double that of the Cu/zeolite adsorbent demonstrated in the literature. INTRODUCTIONThe hydride gas of phosphine (PH 3 ) is used in large quantity for semiconductor, liquid crystal display (LCD), and light-emitting diode (LED) manufacturing industries in various processes. The unutilized PH 3 gas must be abated right after the process tool because of its high toxicity and flammability. In addition, the PH 3 gas is thought to be an airborne molecular contaminant (AMC), which decreases the product yield. Dry chemical adsorption is a preferred method used for hazardous gas removals from these manufacturing factories. It can treat PH 3 effectively, 1-3 especially when the PH 3 coexists with arsine (AsH 3 ) in the exhaust gases. However, commercialized dry chemical adsorbents cannot be reused and they must be treated as hazardous wastes. Thus it is essential to develop a regenerative adsorbent for reducing the amount of hazardous waste production.Earlier researchers 4 treated PH 3 by carbon dry adsorption. The capacity of activated carbon (AC) can reach approximately12 mg-PH 3 /g-AC at 140°C 5 ; however, its disadvantage is its inflammability. 6 The spent carbon might react exothermically with air and result in spontaneous combustion. Thus the AC adsorbent is not practically acceptable in abating the toxic hydride gases for the semiconductor and optoelectronic industries. Li et al. 7 used metal (Cu, Zn, or Mn)-loaded ZSM-5 and Y zeolite adsorbents for the adsorption of PH 3 toxic gas. Their results showed that more than 99% PH 3 adsorption efficiency was achieved when zeolites were loaded with Cu. However, they also revealed that PH 3 removal efficiencies

Preparation and Phosphine Adsorption of Activated Carbon Prepared from Walnut Shells by KOH Chemical Activation

“…The result shows that the MWSAC adsorbent owns the biggest PH 3 breakthrough adsorption capacity and is one of the candidates for PH 3 adsorption removal from yellow phosphorus tail gas. Table 5 (2,4,7,19,22,24,(35)(36)(37) shows that some of the promising experimental performances were obtained with different composite adsorbents. In order to improve PH 3 adsorption capacity, most of the adsorbents are modified by copper (Cu).…”

Effect of Preparation Conditions on the Property Cu/AC Adsorbents for Phosphine Adsorption

“…Li et al (8) treated PH 3 by using Cu=ZSM-5 and Cu=Y zeolite adsorbents and the result showed the maximum adsorption capacity was about 31 mg of PH 3 =g of adsorbents for both Cu=ZSM-5 and Cu=Y zeolites. Copper loaded on the sol-gel-derived c-alumina (Al 2 O 3 ) adsorbents were prepared and tested to investigate PH 3 adsorption removal (9). The result showed that the maximum adsorption capacity of Cu loaded on the solgel-derived c-Al 2 O 3 adsorbent was only 18 mg-PH 3 = g-adsorbent due to the small BET surface area of adsorbent.…”

Adsorption of Trace Phosphine in Circular Hydrogen of a Polysilicon Chemical Vapor Deposition Stove by Cu/γ-Al2O3

“…Of course, there are still several related articles giving us ideas. Copper loaded sol–gel-derived alumina was prepared to capture PH 3 in N 2 , and the cumulative adsorption capacity for five regeneration cycles was 65 mg/g . Rupp et al , have researched the performances of Pd/γ-Al 2 O 3 in cleaning the trace fuel gas of contaminants including PH 3 , AsH 3 , and H 2 Se at high temperature, and results suggested that Pd/γ-Al 2 O 3 sorbent was a great candidate for removing trace PH 3 .…”