FT-IR and solid-state NMR investigation of phosphorus promoted hydrotreating catalyst precursors

• Published in: Journal of catalysis Vol. 132; no. 2; pp. 498 - 511
• Main Authors: Decanio, Elaine C., Edwards, John C., Scalzo, Thomas R., Storm, David A., Bruno, Joseph W.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.12.1991; Elsevier
• Subjects: 02 PETROLEUM; 020400 - Petroleum- Processing; 400201 - Chemical & Physicochemical Properties; ABSORPTION SPECTROSCOPY; ADSORPTION; ALUMINIUM 27; ALUMINIUM COMPOUNDS; ALUMINIUM ISOTOPES; ALUMINIUM OXIDES; ALUMINIUM PHOSPHATES; CALCINATION; CARBON COMPOUNDS; CARBON MONOXIDE; CARBON OXIDES; Catalysis; CATALYST SUPPORTS; CATALYSTS; Catalysts: preparations and properties; CHALCOGENIDES; CHEMICAL REACTIONS; Chemistry; COHERENT SCATTERING; CORRELATIONS; CRACKING; DECOMPOSITION; DIFFRACTION; ELECTROMAGNETIC RADIATION; ELEMENTS; ENERGY SOURCES; Exact sciences and technology; FOSSIL FUELS; FOURIER TRANSFORMATION; FUELS; General and physical chemistry; HYDROCRACKING; HYDROGEN COMPOUNDS; HYDROXYL RADICALS; INFRARED RADIATION; INORGANIC ACIDS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTEGRAL TRANSFORMATIONS; ISOTOPES; LIGHT NUCLEI; MAGNETIC RESONANCE; METALS; MOLYBDATES; MOLYBDENUM; MOLYBDENUM COMPOUNDS; MOLYBDENUM OXIDES; NICKEL; NICKEL COMPOUNDS; NICKEL PHOSPHATES; NONMETALS; NUCLEAR MAGNETIC RESONANCE; NUCLEI; ODD-EVEN NUCLEI; OXIDES; OXYGEN COMPOUNDS; PETROLEUM; PHASE STUDIES; PHOSPHATES; PHOSPHORIC ACID; PHOSPHORUS; PHOSPHORUS COMPOUNDS; PROMOTERS; PYROLYSIS; RADIATIONS; RADICALS; REDUCTION; REFRACTORY METAL COMPOUNDS; RESONANCE; SCATTERING; SORPTION; SPECTROSCOPY; STABLE ISOTOPES; SURFACE PROPERTIES; SYNTHESIS; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; THERMOCHEMICAL PROCESSES; TRANSFORMATIONS; TRANSITION ELEMENT COMPOUNDS; TRANSITION ELEMENTS; VISCOSITY; X-RAY DIFFRACTION; Mixed catalyst; Phosphoric acid; Catalytic reaction; Hydrotreating; Phosphorus; Transition metal; NMR spectrometry; Nickel I Nitrates; Experimental study; Molybdenum; Precursor; Supported catalyst; Calcining; Surface structure; Promoter; Chemical reduction; Infrared spectrometry; Heterogeneous catalysis; Impregnation; Preparation; Group VB element; Nickel; Modified material
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(91)90166-2

The effect of phosphorus on the structure of NiMo/Al 2O 3 hydrotreating catalyst precursors has been investigated. Calcined and reduced P/Al 2O 3, PNi/Al 2O 3, P-Mo/Al 2O 3, and PNiMo/Al 2O 3 (where the wt% P = 0.0 to 10.0, wt% Mo = 8.0 to 12.0, and wt% Ni = 4.0) have been studied using FT-IR, XRD, and 31P and 27Al MAS NMR techniques. Phosphoric acid reacts with alumina hydroxyls forming monomeric and polymeric phosphates. At the higher phosphorus loadings, aluminum phosphate is also formed. On calcined PNi/Al 2O 3, nickel phosphate is formed. This leads to a decrease in density of NO sites in the reduced state as measured by CO adsorption. The addition of up to 1.5 wt% P to Mo(8)/Al 2O 3 promotes the formation of octahedral molybdena on the alumina surface. However, the addition of > 2.0 wt% P results in the formation of bulk M003 and Al 2(MoO 4) 3 in both PMo(8)/Al 2O 3 and PMo(12)/Al 2O 3. CO adsorption on reduced PNi(4)Mo(8)/Al 2O 3 samples shows that the presence of 0.5 wt% P causes a significant increase in the number of sites adsorbing CO. Increasing the P loading further causes a decrease in the number of adsorbing sites; this decrease can be attributed to the formation of either nickel phosphate or nickel molybdate.