Elucidation of Catalysis by Molecular Hydrogen-Originated Protonic Acid Site

氢分子质子酸位点催化作用的阐明

• 批准号: 13450330
• 负责人: HATTORI Hideshi
• 金额: $ 9.41万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450330/
• 关键词: Protonic Acid Site; Rate of Hydrogen Adsorption; Spillover; Solid Acid Catalyst; Alkane Isomerization; Zirconia; 表面プロトン; 水素吸着; 硫酸イオン添加ジルコニア; 酸化タングステン添加ジルコニア; アルカン骨格異性化

The research aims at developing the new concept of "Molecular hydrogen-originated protonic acid site" and elucidating the catalytic features caused by the surface protons formed from molecular hydrogen.To elucidate the factors determining the interaction of hydrogen with the surface of Pt/SO_4^<2->-ZrO_2, the rate of hydrogen adsorption and generation of acidic sites were measured for different types of Pt/SO_4^<2->-ZrO_2 whose surface acidities were controlled. It was revealed that the rate and hydrogen uptake increases with an increase in the surface acidity.It was also proven fro the first time that the formation of protonic acid sites occurs on the surfaces of Pt/WO_3-ZrO_2 and WO_3-ZrO_2 on heating in the presence of hydrogen. The formation of the protons was much easy for Pt/WO_3-ZrO_2 than for WO_3-ZrO_2. The mechanism for the formation of the protons on WO_3-ZrO_2 was elucidated in relation with the surface structure. The kinetic analysis of the hydrogen adsorption revealed that the slow steps were spillover step for Pt/WO3-ZrO2 and and the surface diffusion step for WO_3-ZrO_2.The catalytic activities of Pt/SO_4^<2->-ZrO_2 and Pt/WO_3-ZrO_2 for heptane isomerization were measured to determine the factors governing the selectivity. Pt/WO_3-ZrO_2 exhibited higher selectivity than Pt/SO_4^<2->-ZrO_2 while the conversion rate was higher for Pt/SO_4^<2->-ZrO_2. It was concluded that the selectivity is governed by the acid strength and the rate of surface diffusion of hydrogen. The participation of the spiltover hydrogen in the isomerization mechanisms is clarified.

本研究旨在提出“分子氢源质子酸中心”的新概念，阐明分子氢形成的表面质子的催化特性。为了阐明决定氢与铂表面相互作用的因素，测定了不同类型的表面酸性受控的铂/SO4^&lt；2-&gt；-ZrO2的氢吸附速率和酸性中心的生成。结果表明，随着表面酸度的增加，质子酸的生成速率和吸氢量增加，并首次证实了在有氢存在的条件下加热时，在Pt/WO_3-ZrO_2和WO_3-ZrO_2表面形成了质子酸中心。Pt/WO_3-ZrO_2比WO_3-ZrO_2更容易形成质子。从表面结构的角度解释了WO_3-ZrO_2上质子的形成机理。氢吸附动力学分析表明，催化剂的慢吸氢步骤为溢流步骤和表面扩散步骤。考察了催化剂对正庚烷异构化的催化活性，考察了影响催化剂选择性的因素。Pt/WO_3-ZrO_2催化剂的选择性高于Pt/SO_4~(2-)-ZrO_2催化剂，而Pt/SO_4~(2-)-WO_3-ZrO_2催化剂的转化率高于Pt/WO_3-ZrO_2催化剂。阐明了溢出氢参与异构化反应的机理。

项目成果

S.Triwahyono: "IR Study of Acid Sites on WO_3-ZrO_2 and Pt/WO_3-ZrO_2"Applied Catalysis A : General (電子ジャーナル). 6389. 1-9 (2002)

S.Triwahyono：“WO_3-ZrO_2 和 Pt/WO_3-ZrO_2 上酸性位点的红外研究”应用催化 A：综述（电子期刊）。

S.Triwahyono: "Kinetic study of hydrogen adsorption on Pt/WO_3-ZrO_2 and WO_3-ZrO_2"Applied Catalysis A : General. (in press). (2003)

S.Triwahyono：“Pt/WO_3-ZrO_2 和 WO_3-ZrO_2 上氢吸附的动力学研究”应用催化 A：概述。

S. Triwahyono, T. Yamada, H. Hattori: "Effect of Na Addition, Pyridine, and Water on Hydrogen Adsorption Property of Pt/SO_4^<2->-ZrO_2(Short title : Hydrogen adsorption onPt/SO_4^<2->-ZrO_2)"Catalysis Letter. 85(1-2). 109-115 (2003)

S. Triwahyono、T. Yamada、H. Hattori：“Na Addition、吡啶和水对 Pt/SO_4^<2->-ZrO_2 氢吸附性能的影响（短标题：氢在 Pt/SO_4^<2- 上的吸附”

S.Triwahyono: "Effects of Na Addition, Pyridine, and Water on Hydrogen Adsorption Property of Pt/SO_4^<2->-ZrO_2 (Short title : Hydrogen Adsorption on Pt/SO_4^<2->-ZrO_2)"Catalysis Letter. 85(1-2). 109-115 (2003)

S.Triwahyono：“Na Addition、吡啶和水对 Pt/SO_4^<2->-ZrO_2 氢吸附性能的影响（简称：Pt/SO_4^<2->-ZrO_2 上的氢吸附）”催化快报

S.Triwahyono: "IR Study of Structure of Acid Sites on WO_3-ZrO_2"Applied Catalysis A : General. (in press). (2003)

S.Triwahyono：“WO_3-ZrO_2 上酸位点结构的红外研究”应用催化 A：概述。