We prepared a mullite precursor aerogel from a (di-sec-butoxyaluminoxy)triethoxysilane double alkoxide, The intimacy of mixing that results from the "built-in" Al-O-Si linkages delivers a mullite precursor displaying higher surface area, less Bronsted acid character, and more facile crystallization to mullite than an aerogel of the same composition prepared by a conventional prehydrolysis technique.