STRUCTURE-REACTIVITY RELATIONSHIPS FOR BASIC CATALYSTS DERIVED FROM A MG(2+)/AL(3+)/CO(3)(2-) LAYERED DOUBLE HYDROXIDE

The specific activities of catalysts formed by thermal activation of the layered double hydroxide [Mg2.34Al(OH)6.68](CO3)0.5-2.6H2O have been determined using 2-methyl-3-butyn-2-ol (MBOH) as an acid/base-selective substrate. Acetone and acetylene were the only reaction products formed over the temperature range 80-150-degrees-C, demonstrating that all of the LDH-derived catalysts have highly basic selectivities. Thermal activation below the structural decomposition point of the LDH (less-than-or-equal-to 250-degrees-C) afforded catalysts with specific activities approximately an order of magnitude larger than the amorphous metal oxides and crystalline MgAl2O4 spinel-MgO mixtures formed by thermal activation at 450 and 890-degrees-C, respectively. Even the remnant LDH structure formed by partial decarbonation/dehydroxylation at 350-degrees-C was substantially more active than the more commonly used metal oxide derivatives.