In our previous studies, CuCl 2 showed excellent removal efficiency for trace phosphine in circular hydrogen of a polysilicon chemical vapor decomposition (CVD) stove. In this study, the investigation of properties and performances of CuCl 2 supported on γ-Al 2 O 3 with high surface area were conducted. Various characterization techniques including BET, XRD, TPR, SEM, TGA, and XPS were used to identify the copper species and discuss the adsorption mechanism. The results illustrated that γ-Al 2 O 3 maintained the mesoporous structure and high specific surface area and it was well dispersed on the channel of γ-Al 2 O 3 after impregnation of CuCl 2 . There are two forms of copper species, copper aluminate and amorphous CuCl 2 , generated according to the copper loading. In the adsorption experiment, the virgin γ-Al 2 O 3 has no adsorption capacity for PH 3 . Copper aluminate showed weak adsorption performance, while amorphous CuCl 2 exhibited high reactivity for PH 3 capture. The adsorption capacity of 7.4% Cu/γ-Al 2 O 3 was 32.09 mg/g with an inlet concentration of 50 ppm at 20 °C. Moreover, the chemical adsorption efficiencies of Cu/γ-Al 2 O 3 increased with increasing the adsorption temperature ranging from −15 to 50 °C, but decreased by increasing the concentration of HCl in the inlet gas. After capturing PH 3 in N 2 , the transformation of PH 3 followed the sequence of PH 3 → H 2 P−OH → HOPO → H 3 PO 4 or P 2 O 5 . At the same time, Cu 2+ was reduced to Cu + . Ultimately, H 3 PO 4 and P 2 O 5 were produced and CuCl 2 was regenerated by exposing the spent sample to ambient air for a long time. Partial water molecule may be involved in the adsorption process. The adsorbent can be renewed well by thermal treatment in air atmosphere, and the cumulative adsorption capacity for four cycles is 146.1 mg/g. Cu/γ-Al 2 O 3 can be effectively used as a trace phosphine adsorbent at room temperature.

Operating pressure drop and minimum fluidizing velocity were studied in a flat spout-fluid bed using sub-millimetre grade silicon particles. The influence of introducing a nonporous draft tube of different configurations as well as fluidizing gas on the two parameters was investigated. A comparison of fluidizing gas systems indicated that introduced gas restrained gas bypassing to lower the minimum fluidizing velocity; however, the operating pressure drop was higher than systems without the existence of fluidizing gas. Two new correlations that took into account the effects of bed geometry and fluidizing gas on the operating pressure drop and minimum fluidizing velocity were developed based on the experimental data, which were in agreement with the present experiments.