Preparation and comparison of supported gold nanocatalysts on anatase, brookite, rutile, and P25 polymorphs of TiO2 for catalytic oxidation of CO.
Preparation and comparison of supported gold nanocatalysts on anatase, brookite, rutile, and P25 polymorphs of TiO2 for catalytic oxidation of CO.
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DOI：
10.1021/jp044091o
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发表时间：
2005-05
期刊：
影响因子：
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通讯作者：
Wenfu Yan;Bei Chen;S. Mahurin;V. Schwartz;D. Mullins;A. Lupini;S. Pennycook;S. Dai;S. Overbury
中科院分区：
文献类型：
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作者：
Wenfu Yan;Bei Chen;S. Mahurin;V. Schwartz;D. Mullins;A. Lupini;S. Pennycook;S. Dai;S. Overbury
通过超声和水热法成功地合成了纳米尺寸的金红石型（≤ 10 nm）、金红石型（≤ 10 nm）和板钛矿型（约70 nm）二氧化钛颗粒。通过沉积-沉淀（D-P）工艺将金以高分散性沉积在金红石、金红石、板钛矿和商业二氧化钛（P25）载体的表面上。将所有催化剂暴露于相同顺序的处理和催化CO氧化活性的测量。所合成的催化剂具有高活性，在暴露于反应物流时伴随有Au还原。在423 K下温和还原可使每种载体上的催化剂都具有较高的活性。在高达573 K的温度下进行一系列处理后，观察到四种催化剂的失活。板钛矿负载的金催化剂在所有处理后保持最高的催化活性。XRD和TEM结果表明，经过反应和预处理后，板钛矿上负载的金颗粒比其它载体上的小。
Nanosized anatase (< or = 10 nm), rutile (< or = 10 nm), and brookite (approximately 70 nm) titania particles have been successfully synthesized via sonication and hydrothermal methods. Gold was deposited with high dispersion onto the surfaces of anatase, rutile, brookite, and commercial titania (P25) supports through a deposition-precipitation (D-P) process. All catalysts were exposed to an identical sequence of treatment and measurements of catalytic CO oxidation activity. The as-synthesized catalysts have high activity with concomitant Au reduction upon exposure to the reactant stream. Mild reduction at 423 K produces comparably high activity catalysts for every support. Deactivation of the four catalysts was observed following a sequence of treatments at temperatures up to 573 K. The brookite-supported gold catalyst sustains the highest catalytic activity after all treatments. XRD and TEM results indicate that the gold particles supported on brookite are smaller than those on the other supports following the reaction and pretreatment sequences.