Elucidation of hydrogen spillover phenomenon on solid acid catalysts

固体酸催化剂上氢气溢出现象的阐明

• 批准号: 10450300
• 负责人: FUJIMOTO Kaoru
• 金额: $ 10.75万
• 依托单位: THE UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10450300/
• 关键词: Spillover; Hydrogen; Solid acid; Hydrocarbon Reforming; Bronsted acid; Lewis Acid; Hydride; スピルオーバー現象; 固体酸触媒; プロトン

Solid acid site is the catalytic active site for the isomerization, hydrocracking, disproportionation of hydrocarbons. The problem in these kinds of reaction is the carbon deposition on the solid acid catalyst which are formed by the polymerization, and this deactivates the catalyst. In the case that noble metals are introduced to the solid acid catalyst by supporting or physically mixing, the deactivation is considerably inhibited. It has been reported that the cofeed of hydrogen is very effective to the inhibition of the deactivation. The effect of hydrogen has been expalined by the hydrogen spillover phenomenon. Hydrogen molecule dissociates on metal surface and spills over to the acid site. The spilled over hydrogen regenerates the acid site and supplies the hydride to the hydrocarbon reaction intermediate. We have proposed the reaction mechanism on the basis of the spillover effect. In this study, we observed the behavior of adsorbed pyridine on the acid site under hydrogen flowing by means of FTIR.From the comparison between zeolite supported Pt catalyst and the physical mixture of zeolite with Pt/SiO_2 catalyst, it was found that spillover hydrogen promotes the desorption of adsorbed pyridine on Lewis acid site. This result suggests the formation of hydride as the spillover hydrogen.

固体酸中心是烃类异构化、加氢裂化、脱烃等反应的催化活性中心。这类反应中的问题是在固体酸催化剂上由聚合形成的碳沉积，这使催化剂失活。在通过负载或物理混合将贵金属引入固体酸催化剂的情况下，失活被显著抑制。据报道，氢的共进料对抑制失活非常有效。用氢溢出现象解释了氢的影响。氢分子在金属表面解离并溢出到酸性部位。溢出的氢使酸位点再生并将氢化物供应给烃反应中间体。我们提出了基于溢出效应的反应机制。本文采用FTIR技术研究了氢流动条件下吡啶在沸石酸中心上的脱附行为，通过对沸石负载Pt催化剂和沸石与Pt/SiO_2催化剂物理混合物的比较，发现氢的溢出促进了吡啶在刘易斯酸中心上的脱附。这一结果表明，氢化物的形成作为溢出氢。

项目成果

R.Ueda,K.Tomishige: "Promoting Effect of hydrogen Spillover on Pyridine Migration Adsorbed on Lewis Acid site in USY zeolite"Catalysis Letters. 57. 145-149 (1999)

R.Ueda，K.Tomishige：“氢气溢出对 USY 沸石路易斯酸位点上吸附的吡啶迁移的促进作用”催化快报。

R.Ueda, K.Tomishige, K.Fujimoto: "Nature of spilt-over hydrogen on acid sites in zeolites The observation of the behavior of adsorbed pyridine on Zeolites by means of FTIR"Journal of Catalysis. 194. 14-22 (2000)

R.Ueda、K.Tomishige、K.Fujimoto：“沸石中酸性位点上溢出氢的性质通过 FTIR 观察沸石上吸附吡啶的行为”催化杂志。

R.Ueda,K.Tomishige,K.Fujimoto et.al: "Nature of spilt-over hydrogen on acid sites in zeolites : The observation of the behavior of adsorbed pyridine on zeolite catalysts by means of FTIR"Journal of Catalysis. 194. 14-22 (2000)

R.Ueda、K.Tomishige、K.Fujimoto 等人：“沸石中酸性位点上溢出氢的性质：通过 FTIR 观察沸石催化剂上吸附吡啶的行为”催化杂志。

冨重圭一,藤元薫: "固体酸触媒とスピルオーバー水素種の相互作用"触媒. 41. 374-376 (1999)

Keiichi Tomishige、Kaoru Fujimoto：“固体酸催化剂与溢出氢物种之间的相互作用”，催化 41. 374-376 (1999)。

R.Ueda et al: "Promoting Effect of Hydrogen Spillover on Pyridire Migration Adsorbed on Lewrs Acid Site in USY Zeolite" Catal.lett.(発表予定).

R.Ueda 等人：“氢气溢出对 USY 沸石 Lewrs 酸位点上吸附的吡啶迁移的促进作用”Catal.lett（即将出版）。