Highly dispersed chromium(III) molybdate powders obtained by solid phase synthesis

• Published in: Tonkie himičeskie tehnologii (Online) Vol. 19; no. 6; pp. 547 - 554
• Main Authors: Miroshnichenko, M. N., Kolosov, V. N.
• Format: Journal Article
• Language: English
• Published: MIREA - Russian Technological University 2025
• Subjects: chromium; molybdate; oxide; pores; powder; solid-phase synthesis; specific surface area
• ISSN: 2410-6593; 2686-7575
• DOI: 10.32362/2410-6593-2024-19-6-547-554

Objectives . To obtain highly dispersed powders of chromium(III) molybdate Cr 2 (MoO 4 ) 3 by solid phase synthesis and to study their porous structure. Methods . After stirring in water, a mixture of Cr 2 O 3 and MoO 3 oxide powders was dried in air and subjected to heat treatment in the temperature range of 600–800°C. After heat treatment, the products were identified by X-ray phase and sedimentation analysis. The specific surface area was measured using the Brunauer–Emmett–Teller static adsorption method. Porosity parameters were measured using the Barrett–Joyner–Halenda (BJH) method. Results . The Gibbs free energy ΔG of the reaction between chromium and molybdenum oxides was calculated and it was shown that the process is characterized by a significant negative value of ΔG. Concurrently, the Gibbs energy exhibits a relatively weak dependence on temperature. The highly dispersed chromium(III) molybdate powders with specific surface area of 15.3–29.7 m 2 ·g −1 obtained in this way were pure according to X-ray diffraction analysis. A study of the volume, diameter, and pore size distribution was conducted through the utilization of nitrogen adsorption–desorption isotherms in accordance with the BJH model. Conclusions . It was demonstrated that Cr 2 (MoO 4 ) 3 powders possess a mesoporous structure and are distinguished by a bimodal pore system comprising small pores with a diameter of 2–3 nm and larger pores with a diameter ranging from 15 to 30 nm.