TY - JOUR

T1 - Low-Waste Synthesis and Properties of Highly Dispersed NiO·Al2O3 Mixed Oxides Based on the Products of Centrifugal Thermal Activation of Gibbsite

AU - Zhuzhgov, Aleksey V.

AU - Isupova, Lyubov A.

AU - Suprun, Evgeny A.

AU - Gorkusha, Aleksandr S.

N1 - The study was financially supported by the Russian Science Foundation within project No. 23-23-00241. Публикация для корректировки.

PY - 2023/8

Y1 - 2023/8

N2 - This study revealed an increased reactivity of centrifugally thermoactivated products of gibbsite toward aqueous solutions of nickel nitrate at room temperature as well as under hydrothermal conditions. X-ray, thermal, microscopy, adsorption and chemical analysis methods were used to investigate and demonstrate the possibility of obtaining highly loaded mixed aluminum–nickel oxide systems, with a nickel content of ca. 33 wt.%, using a hydrochemical treatment at room temperature or a hydrothermal treatment of suspensions of the product of the centrifugal thermal activation of gibbsite in aqueous solutions of nickel nitrate. It was shown that the thermal treatment of xerogels—hydrochemical interaction products—in the range of 350–850 °C led to the formation of NiO phases and highly dispersed solid solutions of nickel based on the NiAl2O4 spinel structure, with different ratios and a high specific surface area of 140–200 m2/g. A hydrochemical treatment of suspensions at room temperature ensures that the predominant formation of the NiO phase is distributed over the surface of the alumina matrix after calcination, whereas hydrothermal treatment at 150 °C leads to a deeper interaction of the suspension components at the treatment step, which occurs after the thermal treatment of the formed xerogel in the predominant formation of poorly crystallized NiAl2O4 spinel (“protospinel”). The considered method makes it possible to obtain complex aluminum–nickel oxide systems with different phase ratios, decreases the number of initial reagents and synthesis steps, completely excludes waste and diminishes the total amount of nitrates by 75 wt.% compared to the classical nitrate scheme for the coprecipitation of compounds with a similar elemental composition.

AB - This study revealed an increased reactivity of centrifugally thermoactivated products of gibbsite toward aqueous solutions of nickel nitrate at room temperature as well as under hydrothermal conditions. X-ray, thermal, microscopy, adsorption and chemical analysis methods were used to investigate and demonstrate the possibility of obtaining highly loaded mixed aluminum–nickel oxide systems, with a nickel content of ca. 33 wt.%, using a hydrochemical treatment at room temperature or a hydrothermal treatment of suspensions of the product of the centrifugal thermal activation of gibbsite in aqueous solutions of nickel nitrate. It was shown that the thermal treatment of xerogels—hydrochemical interaction products—in the range of 350–850 °C led to the formation of NiO phases and highly dispersed solid solutions of nickel based on the NiAl2O4 spinel structure, with different ratios and a high specific surface area of 140–200 m2/g. A hydrochemical treatment of suspensions at room temperature ensures that the predominant formation of the NiO phase is distributed over the surface of the alumina matrix after calcination, whereas hydrothermal treatment at 150 °C leads to a deeper interaction of the suspension components at the treatment step, which occurs after the thermal treatment of the formed xerogel in the predominant formation of poorly crystallized NiAl2O4 spinel (“protospinel”). The considered method makes it possible to obtain complex aluminum–nickel oxide systems with different phase ratios, decreases the number of initial reagents and synthesis steps, completely excludes waste and diminishes the total amount of nitrates by 75 wt.% compared to the classical nitrate scheme for the coprecipitation of compounds with a similar elemental composition.

KW - gibbsite

KW - mixed oxides NiO·Al2O3

KW - product of centrifugal thermal activation of gibbsite

KW - protospinel

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85168695212&origin=inward&txGid=5436b1edab8335551f79b2556c6f71be

UR - https://www.mendeley.com/catalogue/d6edcdf8-3ac2-38aa-bc6c-b7fac9b12c79/

U2 - 10.3390/chemengineering7040071

DO - 10.3390/chemengineering7040071

M3 - Article

VL - 7

JO - ChemEngineering

JF - ChemEngineering

SN - 2305-7084

IS - 4

M1 - 71

ER -