TY - JOUR

T1 - Effect of Phosphorus Precursor, Reduction Temperature, and Support on the Catalytic Properties of Nickel Phosphide Catalysts in Continuous-Flow Reductive Amination of Ethyl Levulinate

AU - Wang, Yazhou

AU - Nuzhdin, Alexey L.

AU - Shamanaev, Ivan V.

AU - Kodenev, Evgeny G.

AU - Gerasimov, Evgeny Yu

AU - Bukhtiyarova, Marina V.

AU - Bukhtiyarova, Galina A.

N1 - Funding Information: Funding: This research was supported by the Ministry of Science and Higher Education of the Russian Federation within the governmental order for the Boreskov Institute of Catalysis (project AAAA-A21-121011390055-8). Y. Wang is grateful for the support from the China Scholarship Council. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/2/1

Y1 - 2022/2/1

N2 - Levulinic acid and its esters (e.g., ethyl levulinate, EL) are platform chemicals derived from biomass feedstocks that can be converted to a variety of valuable compounds. Reductive amination of levulinates with primary amines and H2 over heterogeneous catalysts is an attractive method for the synthesis of N-alkyl-5-methyl-2-pyrrolidones, which are an environmentally friendly alternative to the common solvent N-methyl-2-pyrrolidone (NMP). In the present work, the catalytic properties of the different nickel phosphide catalysts supported on SiO2 and Al2 O3 were studied in a reductive amination of EL with n-hexylamine to N-hexyl-5-methyl-2-pyrrolidone (HMP) in a flow reactor. The influence of the phosphorus precursor, reduction temperature, reactant ratio, and addition of acidic diluters on the catalyst performance was investigated. The Ni2 P/SiO2 catalyst prepared using (NH4 )2 HPO4 and reduced at 600◦ C provides the highest HMP yield, which reaches 98%. Although the presence of acid sites and a sufficient hydrogenating ability are important factors determining the pyrrolidone yield, the selectivity also depends on the specific features of EL adsorption on active catalytic sites.

AB - Levulinic acid and its esters (e.g., ethyl levulinate, EL) are platform chemicals derived from biomass feedstocks that can be converted to a variety of valuable compounds. Reductive amination of levulinates with primary amines and H2 over heterogeneous catalysts is an attractive method for the synthesis of N-alkyl-5-methyl-2-pyrrolidones, which are an environmentally friendly alternative to the common solvent N-methyl-2-pyrrolidone (NMP). In the present work, the catalytic properties of the different nickel phosphide catalysts supported on SiO2 and Al2 O3 were studied in a reductive amination of EL with n-hexylamine to N-hexyl-5-methyl-2-pyrrolidone (HMP) in a flow reactor. The influence of the phosphorus precursor, reduction temperature, reactant ratio, and addition of acidic diluters on the catalyst performance was investigated. The Ni2 P/SiO2 catalyst prepared using (NH4 )2 HPO4 and reduced at 600◦ C provides the highest HMP yield, which reaches 98%. Although the presence of acid sites and a sufficient hydrogenating ability are important factors determining the pyrrolidone yield, the selectivity also depends on the specific features of EL adsorption on active catalytic sites.

KW - Ethyl levulinate

KW - Flow reactor

KW - Molecular hydrogen

KW - N-alkyl-5-methyl-2-pyrrolidone

KW - Nickel phosphide

KW - Phosphorus precursor

KW - Reduction temperature

KW - Reductive amination

KW - Support effect

KW - Silicon Dioxide/chemistry

KW - Temperature

KW - Hydrogenation

KW - Amination

KW - Nickel/chemistry

KW - Levulinic Acids/chemistry

KW - Phosphines/chemistry

KW - Catalysis

KW - Phosphorus/pharmacology

UR - http://www.scopus.com/inward/record.url?scp=85122963426&partnerID=8YFLogxK

U2 - 10.3390/ijms23031106

DO - 10.3390/ijms23031106

M3 - Article

C2 - 35163029

AN - SCOPUS:85122963426

VL - 23

JO - International Journal of Molecular Sciences

JF - International Journal of Molecular Sciences

SN - 1661-6596

IS - 3

M1 - 1106

ER -