Low density magnetic silicate-nickel alloy composite hollow structures: seed induced direct assembly fabrication and catalytic properties

An efficient seed induced direct assembly route is designed for the controlled synthesis of hollow microsphere supported catalysts (HMSCs) with nickel alloy as the active material. The inherent magnetic response of nickel alloy endows HMSCs magnetic separability, and the hollow interior of the support opens a new avenue for self-floating separation. It is found that the introduction of P and Co contributes largely to the improvement of the catalytic performance of the products, which may attributed to synergistic effects and electron transfer. Moreover, the loading amounts of alloy nanoparticles can be easily tailored through properly monitoring the reaction conditions. With the optimized loading of 2.68 wt%, the k(N) of HMSC–NiCoP-2.68 wt% reaches 14.0 s(−1) g(−1) for the catalytic reduction of p-nitrophenol (4-NP), which is higher than commercial 5 wt% Pd/C of 11.6 s(−1) g(−1) under the same conditions. This work provides additional insights into preparation and property control of an easily separable supported non-noble metal catalyst, which holds potential to be extended to the preparation and property control of other metal nanocatalysts on various supports.