No abstract

A stable site-isolated mononuclear platinum catalyst with a well-defined structure is presented. Platinum complexes supported in zeolite KLTL were synthesized from [Pt(NH3)4](NO3)2, oxidized at 633 K, and used to catalyze CO oxidation. IR and X-ray absorption spectra and electron micrographs determine the structures and locations of the platinum complexes in the zeolite pores, demonstrate the platinum-support bonding, and show that the platinum remained site isolated after oxidation and catalysis.

No abstract

No abstract

Sorption enhanced steam methane reforming (SESMR) is a promising concept for hydrogen production. The in situ removal of CO 2 shifts the reaction equilibrium toward increased H 2 production as well as H 2 concentration. Generally, most of the previous studies operated the SESMR system using separate materials of a CO 2 adsorbent and a reforming catalyst. In this study, a combined catalyst-adsorbent material (considered as multifunctional catalyst), whose functions are not only to catalyze the reaction but also to adsorb CO 2 simultaneously, was developed and utilized for the SESMR process. CaO and hydrotalcite (MK30-K), wellknown adsorbents for CO 2 capture, were selected as supports to replace a conventional Al 2 O 3 support for Ni catalyst. The material was prepared in the form of powder by incipient wetness technique, and the tests were carried out in the fixed bed reactor system. Experimental results indicated that the activity of Ni/CaO was less than Ni/Al 2 O 3 but high hydrogen concentration in the product stream can be achieved. The effect of Ni loading was investigated, and it was found that at atmospheric pressure, steam to methane ratio of 3 and T = 873 K, 12.5 wt % Ni/CaO was the appropriate ratio, offering high hydrogen concentration (80%). The study also suggested that the use of the multifunctional catalyst eliminates the use of Al 2 O 3 and thus requires a reactor with a smaller size.