Arsenic Adsorption on Copper鈥揚alladium Alloy Films

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• 作者：Karen J. Uffalussy ; James B. Miller ; Bret H. Howard ; Dennis C. Stanko ; Chunrong Yin ; Evan J. Granite
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：May 7, 2014
• 年：2014
• 卷：53
• 期：18
• 页码：7821-7827
• 全文大小：410K
• 年卷期：v.53,no.18(May 7, 2014)
• ISSN：1520-5045

文摘

The adsorption of arsine by copper鈥損alladium alloys was studied using a high-throughput composition spread alloy film (CSAF) sample library. A Cu_xPd_1鈥?i>x CSAF coupon that spanned the complete alloy composition space (x = 0鈥?) was prepared by an evaporative deposition technique. The coupon was exposed to AsH₃ in a N₂ background at 288 掳C in a small flow reactor. Arsenic uptake was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (SEM-EDX), and micro X-ray diffraction (渭-XRD). Pd- and Cu-rich alloy compositions exhibited large surface concentrations of As after exposure to AsH₃. In the Cu-rich alloy, composition and structure measurements suggest the formation of a Cu₃As phase. Arsenic uptake at Pd-rich alloy compositions is consistent with Pd₂As or Pd₈As₃ phases; structural results suggest Pd₂As with a hexagonal structure. In contrast, over a wide range of intermediate compositions (x_Cu 鈮?0.20鈥?.75), little As uptake was observed. These results contribute to a basis for rational design of sorbents for the capture of arsenic from fluid streams, and to an understanding of the stability of palladium鈥揷opper alloy membranes employed for hydrogen separation from coal-derived syngas. This work illustrates the application of high-throughput approaches based on CSAF sample libraries that can be applied to a wide variety of materials development and optimization challenges.