The Effect of Surface Functional Groups on the Dispersion, Chemical Properties, and Catalytic Behavior of Carbon- Supported Pd and Pt-Sn Catalysts Prepared from Metal Cluster

这是一项研究， 分散体上的官能团，耐烧结性，和 钯/碳和铂-锡催化性能 在碳。 战略是以一种可控的方式， 羧基、内酯、羰基、羟基和 高纯度碳上的酚基。 历史上， 这样做的尝试因以下困难而受挫： 表征碳表面。 在这项研究中，碳 表面的特点是反射红外 光谱法、热重分析/质谱法， 和在1000 ℃至2000 ℃下处理后的差示微量热法。 去除所有表面基团，并在空气、氮气中处理后 酸和过氧化氢来选择性地恢复某些 组 制备金属/碳的新方法 催化剂包括钯的合成和浸渍 和铂-锡有机金属络合物， 在低温下还原。 钯的影响 微晶尺寸对磁性和化学性质的影响是 通过磁化率测量确定， 吸附氧气、一氧化碳和氢气， 化学吸附一氧化碳的红外光谱， 固态魔角旋转核磁共振 化学吸附的氢以及钯-105。 这项工作直接涉及碳- 负载贵金属催化剂，但结果也 与碳电极、煤的生产和使用有关 气化和石油重整。 碳支撑 贵金属催化剂广泛应用于该专业 化工和石化行业。

This is a study of the effects of different oxygen-containing functional groups on the dispersion, sinter resistance, and catalytic behavior of palladium on carbon and of platinum-tin on carbon. The strategy is to alter, in a controlled way, the concentrations of carboxyl, lactone, carbonyl, hydroxyl, and phenolic groups on a high-purity carbon. Historically, attempts to do this have been frustrated by the difficulty of characterizing carbon surfaces. In this study, carbon surfaces are characterized by reflection infrared spectroscopy, thermal gravimetric analysis /mass spectrometry, and differential microcalorimetry after treatment at 1000> to remove all surface groups and after treatments in air, nitric acid, and hydrogen peroxide to selectively restore certain groups. Novel approaches to the preparation of metal/carbon catalysts involve the synthesis and impregnation of palladium and platinum-tin organometallic complexes that can be easily reduced at low temperatures. The influence of palladium crystallite size on magnetic and chemical properties is determined by magnetic susceptibility measurements, heats of adsorption for oxygen, carbon monoxide, and hydrogen on the metal, infrared spectra of chemisorbed carbon monoxide, and solid-state magic-angle-spinning nuclear magnetic resonance of chemisorbed hydrogen as well as palladium-105. The work addresses directly the performance of carbon- supported noble-metal catalysts, but the results are also relevant to production and use of carbon electrodes, coal gasification, and petroleum reforming. Carbon-supported noble-metal catalysts are widely used in the specialty chemicals and petrochemicals industries.