Synthesis and structure of a 3D aluminophosphate (PSU-3)

Single crystals of a three dimensional ammonium aluminophosphate (PSU-3) have been synthesized as a minor phase in the synthesis of the unknown cyclohexylamine templated ALPO structure UHM-5, and its structure determined by single crystal X-ray diffraction analysis. The material of composition: NH4·Al2(OH) (PO4)2·2H2O crystallizes in the monoclinic space group P2(1)/n with a = 9.597 Ǻ; b = 9.553 Ǻ; c = 9.957 Ǻ; β = 103.74°. The pore structure comprises a spiral 8-ring pore down the b-axis intersecting with a linear pore down the c-axis; a linear 12-ring pore is parallel to the a-axis. The pores are filled with water, ammonium ions and projecting Al–OH2 groups. Infra-red microscopy showed ammonium but no occlusion of organics in the structure, which like the UHM-5 structure, degrades at ∼300 °C. A parallel gallophosphate experiment produced only a UHM-5 like product.

Figure optionsDownload as PowerPoint slideHighlights
► ALPO structure comprising a 12-ring channel and two intersecting 8-ring channels.
► ALPO built from Al–O–P 3- and 4-rings.
► Ammonium degradation product templated ALPO.
► A new synthesis of ALPO-15 using a cyclohexylamine.