Amorphous aluminum compounds are formed during the synthesis of the γ-Al₂O₃ catalyst precursor. Amorphous compounds influence on the alumina catalyst variously due to different physicochemical properties, which depend on the method of their preparation. In this research, the comparative analysis of physicochemical properties of amorphous aluminum compounds that were obtained by the precipitation method, the thermal decomposition of aluminum nitrate, and alcoxide hydrolysis product were studied. It is the first time that a new method for calculating of quantitative phase composition of amorphous aluminum compounds using the X-ray powder diffraction, thermogravimetric and differential scanning calorimetry analysis, mass-spectrometry, and CHN-analysis was described. Properties of obtaining samples were studied using scanning electron microscopy, low-temperature nitrogen adsorption, and temperature programmed desorption of ammonium analyses. The methods of precipitation and thermal decomposition of aluminum nitrate allows for obtaining non-porous samples consisting of a mixture of amorphous phases (hydroxide and basic salt) that contain the metals impurities and have low acidity of the oxides obtained from them. The highly porous amorphous alumina formed by the thermal decomposition of the alcoxide hydrolysis product with the least amount of impurities and a high acidity of the surface was observed.

Influence exerted by acid-base modifiers of aluminum hydroxide on the texture and acid characteristics of the aluminum oxide support was studied. The effect of the modified aluminum oxides on the charge state of the active component of aluminum-palladium catalysts was determined. It was found that catalysts based on a support with high concentration of strong acid centers are characterized by low conversion of butadiene-1,3 due to the firm chemisorption of the diene on electron-deficient palladium particles. Their formation is due to the strong metal-support interaction. By contrast, catalysts synthesized with supports having a small number of acid centers provide a high conversion of butadiene-1,3.

A study of original iron–potassium catalysts of ethylbenzene (EB) dehydrogenation to styrene and industrially used catalysts: Cat-1 (imported), Cat-2 and Cat-3 (domestic) is performed. Initial samples are multiphase systems consisting of potassium ferrites, hematite, and cerianite (CeO₂). The phase composition of the catalysts after two years of operation consists mainly of magnetite and cerianite, while the amount of potassium (K⁺) in Cat-1, Cat-2, and Cat-3 samples falls by 40, 20, and 26%, respectively. At the same time, K⁺ for the Cat-2 sample is distributed uniformly in granules of the waste catalyst. XRD data indicate the CSR size of its CeO₂ crystals does not change appreciably. The CSR size of CeO₂ crystals in the Cat-3 sample falls from 302 to 110 Å, while it grows from 284 to 419 Å in the Cat-1 sample. After two years of operation, the greatest conversion of EB (72.1%) was observed for the Cat-2 sample, and it fell from 72.3 to 57.4% on the Cat-3 sample. There is a 600–1100% drop in the waste samples’ resistance to crushing, making them unsuitable for further use.