Chemical Capture of Phosphine by a Sol−Gel-Derived Cu/TiO₂ Adsorbent − Interaction Mechanisms

Abstract

In this study, a novel sol-gel-derived Cu/TiO 2 adsorbent has been demonstrated to exhibit exceptional capacities of 40.62, 49.52, and 108.48 mg PH 3 /g Cu/TiO 2 for the oxidative capture of phosphine (PH 3 ) in N 2 , air, and humidified air, respectively. We have proposed the oxidative mechanisms for PH 3 on the Cu/TiO 2 sample on the basis of elemental, chemical state, functional group, and microstructural analysis. Moreover, the influence of O 2 and water vapor on the capture capacity is discussed. The transformation of PH 3 followed the sequence of PH 2 f H 2 P-OH f HP(OH) 2 f P(OH) 3 f HO-PdO f H 3 PO 4 . At the same time, the CuO/Cu(OH) 2 moieties in the TiO 2 lattice were reduced to Cu 0 . The H 2 P-OH and HO-PdO are the two stable intermediates, and they occupied the active species to inhibit further chemisorption. Direct oxidation of PH 3 or the intermediates with adsorbed O 2 was not efficient. However, the Cu/TiO 2 sample catalyzed their interactions via reduction and then oxidation of the Cu 2þ ions. Water vapor acts as a cocatalyst to facilitate the oxidation of the intermediates. The end product, H 3 PO 4 , migrated to bound the TiO 2 support and free the CuO/Cu(OH) 2 for the following catalytic processes. Although competitive adsorption of water molecules initially retarded the adsorption rate, the high extent of oxidation greatly promoted the capture capacity of the Cu/TiO 2 in humidified air.

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

“…As shown in Figure and Table , three P 2p photoelectron lines centered at 129.12, 132.8, and 134.1 eV were obtained after adsorption, which represent P – , P 3+ , and P 5+ , respectively . Likewise, only P 5+ including 95.7% P 2 O 5 and 4.3% H 3 PO 4 was found on Cu/γ-Al 2 O 3 after total oxidation in ambient air.…”

“…As shown in Figure 15 and Table 4, three P 2p photoelectron lines centered at 129.12, 132.8, and 134.1 eV were obtained after adsorption, which represent P − , P 3+ , and P 5+ , respectively. 33 Likewise, only P 5+ including 95.7% P 2 O 5 and 4.3% H 3 PO 4 was found on Cu/γ-Al 2 O 3 after total oxidation in ambient air. This further confirmed that the chemical adsorption is rather accomplished by redox and reduction reaction rather than the simple reaction we estimated before.…”

“…40 Further studies 34 verified that isolated Al−OH groups were essential for the oxidative decomposition of PH 3 into HPO species. Moreover, Chang et al 33 proposed that PH 3 would be converted to H 3 PO 4 with the sequence of PH 2 → H 2 P−OH → HP(OH) 2 → P(OH) 3 → HOPO → H 3 PO 4 via capturing PH 3 by sol−gel-derived Cu/TiO 2 in N 2 , air, and humidified air, respectively. At the same time, Cu 0 would be formed from Cu 2+ at last.…”

Facile Synthesis of Cu Quantum Dots‐TiO2 Nanosheets Schottky Junction and Improved Photocatalytic Degradation Activity

“…What's more, the obvious peak between 940 and 945 eV is identified as the satellite peak of Cu 2+ . It is reported that CuQDs surface is not evitable to be partially oxidized into CuO and Cu(OH) 2 while exposed to ambient air . Besides, XPS is used for surface analysis, while XRD is for bulk analysis.…”

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).…”