ELECTROCATALYSTS BASED ON Ni-, Co-SPINELS
Journal Title: Вісник Одеського національного університету. Хімія - Year 2016, Vol 21, Issue 2
Abstract
The synthesis of Ni-, Co-spinels was performed using coprecipitation method with precursors Ni and Co nitrates under different conditions: using precipitators NaOH and NH4OH, at different pH values and different aging durations. Structural, adsorption and catalytic properties by of Ni-, Co-spinels were determined by X-ray diffraction, desiccator method of adsorption of benzene vapor and in redox reaction of hydrogen peroxide decomposition. The size of the crystallites of obtained spinels was calculated from X-ray diffraction patterns and all of the samples were nano-dispersed with developed surface area from 92 to 320 m2/g. Electrocatalytic investigations have shown that the most active spinels were obtained by precipitation with NH4OH at pH 9,0. The highest catalytic activity from all of the twelve spinels samples in hydrogen peroxide decomposition reaction had Ni-, Co-spinel, precipitated by NH4OH at pH 9,0 and aged for 3 days which shown 100% decomposition degree of H2O2 after 45 seconds of contact. According to the results, the conditions of synthesis of Ni-, Co-spinels highly effect on their catalytic activity. Significantly lower catalytic activity of samples precipitated by NaOH, in our opinion, explained by the inhibitory effect of sodium, which is formed by the heat treatment of samples containing NaOH in trace amounts. Established that with decreasing pH values to neutral the activity of Ni-, Co-spinels increases and with increasing duration of aging of samples their catalytic activity is reduced due to the recrystallization process sediment, resulting in the number of active sites on the surface of Ni-, Co-spinels decreases.
Authors and Affiliations
K. A. Fedoruk, I. N. Ivanenko, I. M. Astrelin, А. P. Burmak
Keywords
Related Articles
- EP ID EP337102
- DOI 10.18524/2304-0947.2016.2(58).74789
- Views 94
- Downloads 0
COMPARATIVE CHARACTERISTICS OF Co(II), Ni (II), Cu(II) COORDINATION COMPOUNDS WITH SOME HYDRAZONES OF PYRUVIC ACID
Сonducted comparative analysis of the coordination compounds of Co2+, Ni2+, Cu2+ with condensation products of 2-(7-bromo-2-oxo-5-phenyl-2,3-dihydro-1H-1,4-benzodiazepin-1-yl) acetohydrazide – Hydazepam (Hydr), nicotinoy...
SYNTHESIS, STRUCTURE AND PROPERTIES OF MIXED-METAL Li-Ge(IV) COMPLEXES WITH CITRIC, TARTARIC AND XYLARIC ACIDS
Different-metal complexes of lithium and germanium(IV) with hydroxycarbonic acids – citric (H4Citr), tartaric (H4Tart) and xylaric (H5Xylar) have been obtained for the first time and characterized by methods of elemental...
COORDINATION COMPOUNDS OF 3D-METALS ACETYLACETONATES WITH THIOSEMICARBAZIDE
Coordination Compounds of 3d-Metals acetylacetonates with Thiosemicarbazide were synthesized. Their physical and chemical properties and structure were studied by conductometry, IR spectroscopy, electronic spectroscopy,...
RESEARCH OF DEGRADATIONS OF NANOSTRUCTURES IN THE SALINE MELT EuF2 – NaCl – KCl BY SPECTROSCOPIC METHODS
Methods of luminescent spectroscopy, spectroscopy of diffuse refl ectance and IR transmittance spectroscopy were used for investigation of process of change of nanostructures of Europium (ІІ) fl uoride in stiffened salin...
MOLECULAR COMPLEXES OF SULPHUR DIOXIDE WITH N,O-CONTAINING ORGANIC BASES (REVIEW)
The literature data on the synthesis, stoichiometry, structure and relative stability of molecular complexes of sulphur dioxide with N,O-containing organic bases have been systematized and generalized. It was shown tha...