Abstract
Supported gold catalysts derived from interaction of a Au–phosphine complex Au(PPh 3)(NO 3) ( 1) with conventional titanium oxide TiO 2 and as-precipitated titanium hydroxide Ti(OH) ∗ 4 (*, as-precipitated) have been characterized by means of XRD, XPS, EXAFS, and 31 P CP/MAS–NMR. The Au complex 1 was supported on TiO 2 and Ti(OH) ∗ 4 without loss of Au–P bonding at room temperature. The Au complex 1 on TiO 2 was readily and completely decomposed to form metallic gold particles by calcination at 473 K, whereas only a small part of the complex 1 on Ti(OH) ∗ 4 was transformed to metallic gold particles. By calcination of 1/ Ti(OH) ∗ 4 at 573 K the formation of both metallic gold particles and crystalline titanium oxides became notable as evidenced by XRD, XPS and 31 P CP/MAS–NMR. The mean diameter of Au particles in 1/ Ti(OH) ∗ 4 calcined at 673 K was less than 30 Å as estimated from Au(2 0 0) diffraction, which was about one-tenth of that for the corresponding 1/TiO 2. Thus the as-precipitated titanium hydroxide Ti(OH) ∗ 4 was able to stabilize the Au complex 1 to lead to the simultaneous decomposition of Au complex and Ti(OH) ∗ 4 . The catalyst 1/ Ti(OH) ∗ 4 calcined at 673 K afforded remarkably high catalytic activity for low-temperature CO oxidation at 273–373 K as compared to the catalyst 1/TiO 2.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
