Two hydrotalcite-based catalysts have been prepared to investigate the effect of synthesis methods on the catalyst behavior in ethanol dehydrogenation to acetaldehyde. On the first one, PdZn/Mg(Al)O_x, Pd and Zn were impregnated on the hydrotalcite support while on the second one, PdZn/Mg(Al)(Pd)(Zn)O_x, Pd and Zn were both incorporated during the support synthesis. Extensive catalyst characterization such as EXAFS, XPS, STEM, XRD,… allowed concluding that impregnation of the active metals gives rise to larger nanoparticles compared to incorporation. Impregnation provokes incomplete reduction, yielding nanoparticles with a PdZn shell and a Pd core. More homogeneously alloyed nanoparticles were obtained after incorporation. The higher methane selectivity on the impregnated catalyst is in agreement with the less uniformly alloyed nanoparticles, which more likely exhibit adjacent Pd-sites promoting product acetaldehyde decomposition. Overall, incorporation gave rise to the most active and selective catalyst to acetaldehyde for ethanol dehydrogenation to acetaldehyde.

制备了两种基于水滑石的催化剂，以研究合成方法对乙醇脱氢制乙醛中催化剂行为的影响。在第一个上，PdZn / Mg（Al）O _x，Pd和Zn浸渍在水滑石载体上，而在第二个上，PdZn / Mg（Al）（Pd）（Zn）O _x在载体合成过程中，Pd和Zn均被掺入。广泛的催化剂表征，例如EXAFS，XPS，STEM，XRD等，可以得出结论，与掺入相比，活性金属的浸渍产生了更大的纳米颗粒。浸渍引起不完全还原，产生具有PdZn壳和Pd核的纳米颗粒。掺入后获得更均匀合金的纳米颗粒。在浸渍的催化剂上较高的甲烷选择性与不那么均匀合金化的纳米颗粒一致，纳米颗粒更可能显示出相邻的Pd位，从而促进产物乙醛的分解。总的来说，掺入产生了对于乙醛的最具活性和选择性的催化剂，用于乙醇脱氢为乙醛。