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应用原位M(?)ssbauer谱考察了Al_2O_3、MgO、SiO_2及AC(活性炭)等载体负载的铂锡催化剂中锡组分的存在状态。结果发现:(1)PtSn/Al_2O_3还原后,锡组分仍为氧化态;(2)PtSn/MgO及PtSn/SiO_2还原后有部分零价锡生成并与金属铂形成了Sn~o/Pt~o合金;(3)PtSn/AC还原后所生成的零价锡则以游离态存在。这些结果为进一步了解催化剂中锡组分价态及存在方式对负载型铂锡催化剂反应性能的影响奠定了基础。
In situ M (?) Ssbauer spectra were used to investigate the presence of tin components in platinum-tin catalysts supported by Al 2 O 3, MgO, SiO 2 and AC (activated carbon). The results show that: (1) after the reduction of PtSn / Al_2O_3, the tin component is still in an oxidation state; (2) some of the zero-valent tin is formed after PtSn / MgO and PtSn / SiO_2 reduction and forms Sn ~ o / Pt ~ o alloy; (3) PtSn / AC generated after the reduction of zero-valent tin exists in free state. These results provide a basis for further understanding of the influence of the valence state and the mode of presence of tin components in the catalyst on the performance of the supported platinum-tin catalysts.