Bulky olefin epoxidation under mild conditions over Mo-based oxide catalysts

resumo

Molybdenum-based epoxidation catalysts are among the most investigated since the homogeneous Mo-based catalytic process claimed by Halcon International Inc. for liquid phase olefin epoxidation (EPO). While homogeneous Mo-based catalytic technologies reached industrial implementation for olefin EPO, the same does not apply for heterogeneous Mo-based ones, which have not reached industrial implementation (e.g., to meet catalyst productivity and stability requirements). In this work, EPO nanocatalysts consisting of oxides possessing molybdenum and M = Ta, Nb or W were prepared via a simple, versatile methodology. The influence of the material synthesis conditions on the material properties was investigated to meet superior catalytic performances. Promising Mo-based solid catalysts were obtained which promoted the EPO of relatively bulky olefins such as fatty acid methyl esters (methyl oleate, methyl linoleate), using tert-butyl hydroperoxide as oxidant under mild conditions; e.g., the materials Mo(75D)M-0.3 with M = Nb, W (75 at% Mo relative to M, and MoO2Cl2 as precursor), obtained in a fast synthesis of 0.3 h, led to 92-96% epoxide selectivity at 84-95% methyl oleate conversion, at 70 degrees C. To the best of our knowledge, these are the first Mo,M oxides reported for these reactions. Epoxidation of bulky olefins, such as biobased fatty acid methyl esters (FAMEs), with tert-butylhydroperoxide (TBHP), under mild conditions, was promoted by nanocatalysts possessing Mo and M = Ta, Nb or W, prepared via simple, versatile methodology.

palavras-chave

ACID METHYL-ESTERS; MOLYBDENUM DIOXIDE; HYDROGEN-PEROXIDE; SILICA CATALYSTS; PROPYLENE-OXIDE; TANTALUM OXIDE; BINARY OXIDES; PROPENE OXIDE; HPPO PROCESS; SURFACE

categoria

Chemistry

autores

Gomes, DM; Yao, XY; Neves, P; Pinna, N; Russo, PA; Valente, AA

Grupos

G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Conversao catalitica de olefinas derivadas da biomassa (BiOle_AcidOxCat)

agradecimentos

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC), and by Project POCI-01-0145-FEDER-030075 (COMPETE 2020 Operational Thematic Program for Competitiveness and Internationalization), co-financed by national funds through the FCT/MCTES and the European Union through the European Regional Development Fund under the Portugal 2020 Partnership Agreement. D. M. G. (grant ref. 2021.04756.BD) acknowledges the FCT for PhD grant (State Budget, European Social Fund (ESF) within the framework of Portugal 2020, namely through the Centro 2020 Regional Operational Program). The authors are very grateful to Doctor M. Rosario Soares (CICECO-Aveiro Institute of Materials) for the discussions and kind assistance with the PXRD studies. C. Erdmann is acknowledged for the TEM measurements. X. Y. thanks the China Scholarship Council (CSC).