The present invention provides a process for producing an alkylaromatic compound comprising the step of contacting an alkylatable aromatic compound with an alkylating agent under alkylation conditions in the presence of a alkylation catalyst comprising phosphorus and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including the d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom.