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Humic Acid Modified Applied Palladium Catalysts for Nitro Compounds Reduction
(2023-01-01)
Индира Мухаметкеримовна Джелдыбаева
;
Zhaksyntay K. Kairbekov
;
Manshuk Z. Esenalieva
;
Altay Zh. Kairbekov
;
S.M. Suimbayeva
This work studies the possibility of using humic acids (HA) as a natural polymer-modifier for applied palladium catalysts.New catalysts based on palladium -HA fixed on the carrier bauxite-094 (B-094) have been synthesized and their catalytic properties in the process of reducing p-nitrodiethylaniline (PNDA) and potassium o-nitrophinolate (PtONPh) have been studied.Humic acid is a non-toxic, inexpensive, easily accessible high molecular weight polymer.Therefore, its use as a modifier polymer for applied palladium catalysts in the processes of hydrogenation of nitro compounds is very cost-effective and relevant as of today.This work presents the results of studies on different methods for the preparation of polymer metal catalysts.It has been shown that HA has stronger acid and sorption properties, greater branching and asymmetry of macromolecules.It has been established that the activity and stability of polymer-metallic complexes (PMC) based catalysts depend on the sequence of application of the active phase on the carrier.The largest specific surface area is characterized by the catalyst 1.0% Pd-HA (1.0%)/B-094, which exhibits the greatest activity and stability in the reduction reactions of PNDA and PtONPh.Considering that HA (polymer) and bauxite-094 (carrier) are materials of natural origin, the development of such catalysts is not accompanied by large economic costs, which is one of the main requirements for modern catalysts.
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Antioxidant Activity and Bioavailability of Humic Substances of Low-Mineralized Sulphide Mud
(2023-01-01)
Ж. К. Каирбеков
;
S.M. Suimbayeva
;
Индира Мухаметкеримовна Джелдыбаева
;
Manshuk Z. Esenalieva
;
А.Ж. Каирбеков
Humic substances (HS) are natural compounds, the formation of which occurs in natural environments as a result of chemical and biological decomposition.HS accounts for 60% to 80% of organic matter in soil and aquatic environment.Therefore, we obtained samples of HS isolated from low-mineralized sulphide mud deposits of Tuzkol Lake (Republic of Kazakhstan) were obtained.HS samples have been characterized by instrumental methods: EPR spectroscopy and amperometry.Analysis of the concentration of paramagnetic centers shows that the minimum number of free radicals contains molecules of fulvic acids, and the maximum number of free radicals contains molecules of humic acids (HA) of peloids.The antioxidant activity and bioavailability of humic preparations in the form of sodium humates depending on the concentration of HS have been investigated.The information obtained indicates that HS have antioxidant activity and bioavailability, the value of which increases when the concentration of the solution grows.Dialysis of silver humate has been carried out in the presence of dimethyl sulfoxide (DMSO) at concentrations of 0.1; 1.0; 5.0 and 10% w/w.For HA and silver humate, a 10% concentration of DMSO is optimal, which allows a maximum yield of peloid preparations and a 1.6-fold increase in permeability.Dialysis of silver humate is 1.2 times more intensive than dialysis of HA.It has been shown that the change in the total content of antioxidants in various fractions of humic substances increases in the series; fulvic -humic -gimatomelanic acids.
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