A new microporous europium-containing metal–organic framework [Eu2(μ2-pzdc)(μ4-pzdc)(μ2-ox)(H2O)4]·8H2O (1) (H2pzdc = 2,5-pyrazinedicarboxylic acid, H2ox = oxalic acid) has been hydrothermally synthesized via an unprecedented in situ formation of 2,5-pyrazinedicarboxylate (pzdc) and oxalate (ox) ligands. Structure 1 was characterized by both single-crystal and powder X-ray diffraction analysis. It can be described as a 4-connected binodal Moganite network with the Schläfli symbol of (4·64·8)2(42·62·82), which exhibits a reversible and highly selective sensing function with respect to acetone.