A new family of Al-based MOFs denoted as CAU-3 (CAU = Christian-Albrechts-Universität) was discovered in the solvothermal system Al³⁺/aryldicarboxylic acid/NaOH/methanol by applying high-throughput-methods. The three compounds reported in this article [Al₂(OCH₃)₄BDC], [Al₂(OCH₃)₄BDC-NH₂] and[Al₂(OCH₃)₄NDC] (BDC = 1,4-benzenedicarboxylate; NDC = 2,6-naphtalenedicarboxylate) are all based on the same unprecedented inorganic building unit [Al₁₂(OCH₃)₂₄]¹²⁺, which is a dodecameric cyclic aluminium-methanolate-cluster. The material CAU-3-NDC was found to exhibit the highest surface area as well as the highest micropore volume of all Al-based MOFs reported until now.