Chemical
decarboxylation of l-lysine is a promising route
for producing cadaverine, which is the key monomer of new polyamide,
polyurethane, and nylon materials. Currently, the wide application
of Ru-based catalysts is restricted by its low efficiency which was
mainly caused by the severe agglomeration of ruthenium nanoparticle.
In this study, manganese (Mn) doped ruthenium oxide catalyst was synthesized
through the wetness impregnation method with Beta zeolite as the candidate
support for efficient decarboxylation of l-lysine to cadaverine.
Structure characterization showed that RuO2 was the main
phase of ruthenium oxide nanoparticles. The prepared Ru–Mn/Beta
catalysts exhibited a high dispersion of ruthenium oxide nanaoparticle
on Beta, which maximized the utilization of active sites. Meanwhile,
abundant oxygen vacancies were generated after Mn doping to balance
the charge of the disturbed long-term periodic structure in the RuO2 crystalline, which greatly facilitated the adsorption and
activation of l-lysine by the capture of carboxylic groups.
A full conversion was obtained with Ru–Mn/Beta, and a selectivity
of cadaverine up to 54% was reached in a short time of 1.5 h. The
cadaverine production rate in Ru–Mn/Beta was 60.8 mg/L/min,
which was almost triple that in Ru/Beta (17.7 mg/L/min). The synergetic
catalysis of metal active sites and oxygen vacancies provides a new
opportunity to design efficient catalyst of decarboxylation of amino
acids.
Modified nickel-boride (Ni-B)-based amorphous alloy catalysts used for microwave-assisted catalytic transfer hydrogenation (CTH) of fatty acid methyl esters (FAMEs) had been synthesized via chemical reduction method by adding simultaneously cetyltrimethylammonium bromide (CTAB) and various transition metals. The results suggested that Cr-doped Ni-B-CTAB catalyst showed superior catalytic activity. It was found that Ni-Cr-B-CTAB catalyst remained an amorphous structure and had a smaller particle size with less agglomeration as compared with Ni-B catalyst. What's more, the specific surface area of the catalyst increased obviously with the addition of CTAB and Cr into Ni-B catalyst. Under the established optimum conditions of CTH using Ni-Cr-B-CTAB as a catalyst, the conversion ratio of methyl linoleate reached 78.05% and the properties of hydrogenated FAMEs were improved obviously. This work has provided a feasible approach to prepare a new and efficient Ni-Cr-B-CTAB amorphous alloy catalyst for the CTH of FAMEs and thus to obtained the high-quality hydrogenated FAMEs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.