The Influence of Size and Shape of Pd Nanoparticles on the Performances of Pd/Beta Catalysts for n‐Heptane Hydroisomerization

Several Pd/Beta catalysts with cubic (9 nm, 12 nm, 16 nm) and truncated‐octahedral (18 nm) Pd nanoparticles (NPs) were prepared to investigate the effect of size and shape of Pd NPs for n‐heptane hydroisomerization. Characterizations confirmed that the cubic Pd NPs solely exposed {100} crystal plane and truncated‐octahedral Pd NPs were enclosed by {100} and {111} crystal planes, and that the desorption temperature of subsurface hydrogen on Pd NPs showed size and shape dependence. Hydroisomerization results exhibits that the catalyst with 9 nm cubic Pd NPs displayed the higher isomers selectivity compared to the catalyst with 12 nm cubic NPs, 18 nm truncated octahedral NPs and 16 nm cubic NPs at similar conversion. This result suggested the size and shape dependence of (de)hydrogenation activity of Pd NPs, and further revealed the key role of subsurface hydrogen in determining the (de)hydrogenation activity. Are you in shape? The effect of size and shape of Pd nanoparticles on the performance of bifunctional catalysts were investigated by model catalysts prepared with well‐defined (cube and truncated octahedron) Pd NPs of different sizes. It was found that subsurface hydrogen plays a key role in determining the (de)hydrogenation activity.