Why is the catalyst Copper Chloride faster at the decomposition of hydrogen peroxide than Postassium Iodide and Lead Oxide

We are supposed to prepare a probable scheme to separate a mixture of 3 components: the first will be an acid (or base) organic compound, the second will be a neutral organic compound, and the third will be 1,4-dibromobenzene. I know how to separate the acid (or base) component. However, the remaining 2 neutral compounds in the dichloromethane solution I'm not sure how to deal with. For most of them, I know I can use fractional distillation, as their melting/boiling points are very different, but there is one possibility of the 1,4-dibromobenzene with benzil and the melting points are so close to each other that the fractional distillation may not be possible. Is there another way to separate and purify these? Please no copy/paste responses - they will not get the ratings. I need to know exactly how (and why).