Yolk-Shell-Structured CuO-ZnO-In2O3 Trimetallic Oxide Mesocrystal Microspheres as an Efficient Catalyst for Trichlorosilane Production

Trichlorosilane (TCS), the primary chemical feedstock for production of high-purity Si used in Si-based solar cells, is currently manufactured industrially via a non-catalytic hydrochlorination of metallurgical Si. This process generates a huge amount of undesirable silicon tetrachloride (STC) byproduct. Here we report the synthesis of yolk-shell-structured CuO-ZnO-In2O3 trimetallic oxide mesocrystal microspheres that can be employed as an efficient catalyst to produce TCS catalytically. The CuO-ZnO-In2O3 microspheres with multiple hetero-interfaces were prepared using a facile solvothermal reaction followed by calcination. We found that differing from a single CuO mesocrystal, the electronic density on Cu atoms in the CuO phase within CuO-ZnO and CuO-ZnO-In2O3 can be tuned by varying the composition. When used as a catalyst for Si hydrochlorination reaction to produce TCS, CuO-ZnO-In2O3 shows excellent catalytic performance with very high Si conversion and TCS selectivity. Under the same reaction conditions, the TCS yield increased 13 times relative to the catalyst-free process. This work demonstrates the possibility to decrease the amount of STC needed for the catalytic manufacture of TCS, and provides an approach to the facile synthesis of multi-component mesocrystal materials with a specific structure.