CO hydrogenation over a hydrogen-induced amorphization of intermetallic compound CeNi2

High Catalytic Activity of Hydrogenation of Ethylene over an Amorphous CeNi<SUB>2</SUB>H<I><SUB>x</SUB></I>

“…In order to reveal incompletely understood factors, a favorable reaction of CeNi 2 before/after hydrogen absorption could be oxygen-free reaction system such as olefin hydrogenation to avoid the oxidation. 13) In this paper, we report that an amorphous CeNi 2 H x shows much higher activity than an intermetallic CeNi 2 in hydrogenation of C 2 H 4 , and verify that the high activity is originated from amorphous structure itself where the absorbed hydrogen is not compensated in the reaction.…”

“…The BET surface area (a S,BET ) of intermetallic CeNi 2 and amorphous CeNi 2 H x was estimated to be 0.13 and 0.17 m 2 g À1 as in our previous papers. 12,13) The surface area of CeNi 2 before and after hydrogen absorption was almost the same. Figure 2 shows C 2 H 4 conversion to C 2 H 6 in % for hydrogenation of C 2 H 4 as a function of temperature over the intermetallic CeNi 2 and amorphous CeNi 2 H x .…”

“…Characterization by BET method has been described elsewhere. 12,13) Hydrogenation of C 2 H 4 was proceeded in a standard fixedbed flow reactor where a mixture gas of H 2 /C 2 H 4 ¼ 14;…”

“…[4][5][6][7][8][9][10][11] Very recently, we have reported the unique catalytic performance for hydrogen-induced amorphization (HIA) of CeNi 2 under CO hydrogenation, highlighting that HIA has a potential of new preparation method and activation treatment for IMCs used as catalysts. 12,13) HIA is very interesting phenomenon because of the reverse transformation from the crystalline state into the amorphous one by hydrogen absorption. 14) Moreover, there is a wide variety of HIA conditions according to the alloy systems from low pressure and/or temperature to high pressure and/or temperature, 15) allowing to choice any IMCs suitable for a specific catalytic reaction.…”

“…12) Thus, to verify that a hydride do have catalytic function, it is indispensible to understand the role of absorbed hydrogen or adsorbed hydrogen on catalytic reactions. In order to reveal incompletely understood factors, a favorable reaction of CeNi 2 before/after hydrogen absorption could be oxygen-free reaction system such as olefin hydrogenation to avoid the oxidation.…”