فهرس المقالات Catalytic oxidation

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  1 - A Simple and an Effective Catalyst for Determination of Cefixime in Real Samples Using of Modified Carbon Paste Electrode with Cobalt Impregnated Zeolite
  Samaneh Tajjedin Banafsheh Norouzi
  Carbon paste electrode modified with cobalt impregnated zeolite was prepared by mixing of cobalt_zeolite (Co_Z) and graphite powder with different percent. The electrochemical oxidation of cefixime at such electrodes was investigated using the cyclic voltammetric and am أکثر

  Carbon paste electrode modified with cobalt impregnated zeolite was prepared by mixing of cobalt_zeolite (Co_Z) and graphite powder with different percent. The electrochemical oxidation of cefixime at such electrodes was investigated using the cyclic voltammetric and amperometric techniques. It is not electrochemically active towards cefixime oxidation in 0.1 M phosphate buffer solution (pH=7) on a carbon paste electrode modified with zeolite. The presence of cobalt ions in the zeolite matrix, by soaking the electrode in an aqueous Co(NO3)2 solution, markedly enhances the electrocatalytic activity which was found to depend on the cobalt content. However, the electrocatalytic activity depends on different percent of Co_Z. Under the selected conditions, the anodic peak current was linearly dependent on the concentration of cefixime in the range 0.003–8 mM with the cyclic voltammetric method. The detection limit (S/N=3) was also estimated to be 2.98 μM. Finally, this method was applied for the determination of cefixime in tablet samples. تفاصيل المقالة
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  2 - Electrocatalytic Determination of Anti-Cancer Drug Imatinib, Using Ni Nanoparticle Modified Carbon Paste Electrode
  Fatemeh Khakpoor Shahla Fathi
  In this research, nickel nanoparticles were synthesized by non-aqueous polyol method and morphology of nanoparticles was studied using scanning electron microscopy. Then Ni nanoparticle modified carbon paste electrode was prepared. Electrochemical behavior of modified e أکثر

  In this research, nickel nanoparticles were synthesized by non-aqueous polyol method and morphology of nanoparticles was studied using scanning electron microscopy. Then Ni nanoparticle modified carbon paste electrode was prepared. Electrochemical behavior of modified electrode was studied in basic solution, using cyclic voltammetry and chronoamperometry methods. A pair of oxidation-reduction peaks relating to Ni(OH)2/ NiOOH redox couple was observed in cyclic voltammogram of this electrode. Also, the electrochemical behavior of this electrode in presence of imatinib drug was studied. Results show that this modified electrode has a good ability for electrocatalytic oxidation of imatinib in basic solution. In presence of imatinib, current intensity of oxidation peak of electrode was increased, depending on its concentration. Linear dynamic range, limit of detection and rate constant of electrocatalytic reaction were determined using cyclic voltammetry and chronoamperometry methods. Amount of limit of detection (LOD) in cyclic voltammetry and hydrodynamic amperometry methods were calculated 1.2 × 10 -6 M and 3.5 × 10-7M respectively. Finally, the proposed sensor was successfully applied for determination of imatinibin real samples such as tablet and human blood plasma. تفاصيل المقالة
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  3 - Electrocatalytic oxidation of formaldehyde on novel composite of nickel/triton-x100/poly(o-aminophenol-co-aniline)
  Sepide Saeedi Kenari Shahla Fathi Fereshteh Chekin
  Oxidation of formaldehyde (HCHO) is very important, owing to its use in fuel cells. Modification of electrodes surfaces is an excellent way to decrease the overpotentials as well as to increase the current density of the voltammetric response.pt as most efficient metal أکثر

  Oxidation of formaldehyde (HCHO) is very important, owing to its use in fuel cells. Modification of electrodes surfaces is an excellent way to decrease the overpotentials as well as to increase the current density of the voltammetric response.pt as most efficient metal catalyst can easily be poisoned by product of oxidation and also it has high cost. In this work an efficient and low cost electrocatalytic system for electrochemical oxidation of formaldehyde in alkaline solution is introduced. For preparation of this modified electrode, copolymeric film on the surface of carbon paste electrode was formed by successive potential cycling in solution containing o-aminophenol and aniline as monomer and Triton X-100 as a surfactant. Ni(II) ions were incorporated into the electrode surface by immersion of the copolymeric modified electrode in 0.1 M Ni(II) ion solution. The influences of different parameters such as mol ratio of monomers in copolymer formation and the number of potential cycling for copolymer formation on electrocatalytic ability of the modified electrode for formaldehyde oxidation have been investigated and optimized.Results show that modified electrode with copolymeric films, show higher catalytic effect for formaldehyde oxidation respect to pure homopolymers (polyaniline or poly(o-aminophenol)). Also addition of Triton -X100 in electropolymerization step, considerably increased catalytic ability of the modified electrode for formaldehyde oxidation. This modified electrode displays a highly efficient electrocatalytic activity toward oxidation of formaldehyde. The current density of 11 mA cm-2 is greater than most of the previously reported electrodes. تفاصيل المقالة
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  4 - Formaldehyde measurement based on its electrocatalytic oxidation by Ni-TiO2 nanoparticles/chitosan modified carbon paste electrode as an effective method
  Ebrahim Zarei Mohammad Reza Jamali Jaber Bagheri
  In this work, for the first time, a new and effective bulk modified carbon paste electrode (CPE) was prepared by TiO2 nanoparticles and chitosan and then Ni2+ ions were incorporated to this electrode by immersion of the modified electrode in nickel chloride solution. Th أکثر

  In this work, for the first time, a new and effective bulk modified carbon paste electrode (CPE) was prepared by TiO2 nanoparticles and chitosan and then Ni2+ ions were incorporated to this electrode by immersion of the modified electrode in nickel chloride solution. The values of electron transfer coefficient, charge-transfer rate constant and electrode surface coverage for Ni(II)/Ni(III) redox couple of the TiO2/chitosan modified carbon paste electrode (Ni-TiO2/CHIT/CPE) were found to be 0.66, 3.28 × 10-1 s-1 and 5.14 × 10-8 mol cm-2, respectively. The prepared Ni-TiO2/CHIT/CPE material was characterized by scanning electron microscopy and X‐ray diffractometry. The electrochemical behaviour of the Ni-TiO2/CHIT/CPE towards oxidation of formaldehyde was evaluated and proved. The effects of various factors on the efficiency of electrocatalytic oxidation of formaldehyde were optimized. Under the optimized condition, a calibration curve was obtained in the linear dynamic range of 2.80 × 10-4 to 2.50 × 10-2 mol L-1 with detection limit of 7.14 × 10-5 mol L-1 (3σ/slope) for formaldehyde determination. Also, the method was successfully applied for formaldehyde measurement in the real sample. تفاصيل المقالة
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  5 - Catalytic oxidation of airborne toluene by using copper oxide supported on a modified natural diatomite
  Seyed Reza Azimi Pirsaraei Hasan Asilian Mahabadi Ahmad Jonidi Jafari
  The catalytic oxidation of toluene over copper oxide supported on natural diatomite was investigated. The catalyst was prepared by the wet impregnation method and characterized by using the Brunauer Emmett Teller (BET), field emission Scanning Electron Microscopy (FESEM أکثر

  The catalytic oxidation of toluene over copper oxide supported on natural diatomite was investigated. The catalyst was prepared by the wet impregnation method and characterized by using the Brunauer Emmett Teller (BET), field emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Temperature-programmed reduction (TPR) analysis. The highest catalytic performance for airborne toluene oxidation was obtained at 14 wt% Cu loading. The toluene conversion at 270°C and 380°C, were 50% and 90%, respectively. According to the results of GC/MS and formation the CO2 in effluent gas, no intermediates such as CO or other hydrocarbons were detected and the selectivity towards CO2 was almost 100%. تفاصيل المقالة
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  6 - Enhancement of photocatalytic degradation of 4-nitrophenol by integrating Ag nanoparticles with ZnO/HZSM-5 nanocomposite
  Baharak Divband Azadeh Jodaei Masumeh Khatamian
  In this paper, Ag/ZnO/HZSM-5ternary nanocomposites with different Ag loadings were prepared by the photo precipitation method. The prepared photocatalysts were characterized by XRD, BET, SEM and TEM. The photocatalytic activity of ZnO/HZSM-5 for 4-nitrophenol (4-NP) deg أکثر

  In this paper, Ag/ZnO/HZSM-5ternary nanocomposites with different Ag loadings were prepared by the photo precipitation method. The prepared photocatalysts were characterized by XRD, BET, SEM and TEM. The photocatalytic activity of ZnO/HZSM-5 for 4-nitrophenol (4-NP) degradation was increased by silver doping. Effects of various parameters such as the initial concentration of 4-NP, pH and Ag loading on 4-NP degradation were studied. The best activities were obtained for the 3% Ag-10% ZnO/HZSM-5 nanocatalysts at pH 7.9, 1 g L−1 of the catalyst and 5 ppm of 4-NP. Langmuir–Hinshelwood (L–H) model was proposed for the rate equation of the 4-NP degradation. تفاصيل المقالة
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  7 - Layered double hydroxides: Novel nanocatalysts for combustion of gaseous toluene from polluted air
  Sepideh Naghel-Danaei Seyed Ali Hosseini Aligholi Niaei
  The catalytic performance of Ni-Al, Mg-Al, and Co-Ni LDHs as novel nanocatalysts was evaluated in the oxidation of toluene. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). أکثر

  The catalytic performance of Ni-Al, Mg-Al, and Co-Ni LDHs as novel nanocatalysts was evaluated in the oxidation of toluene. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The XRD and FTIR approved the structure and functional groups of the LDH, respectively. Also, the presence of cations with different oxidation state confirmed by XRD. According to this result, Mars Van Krevelen (MVK) mechanism was suggested for the combustion of toluene over the LDH nanocatalysts. The SEM results indicated that the nanostructure and layered morphology of the catalysts. All LDHs exhibited catalytic activity for toluene oxidation. T80 (temperature for 80% conversion for toluene) for Co-Ni, Ni-Al and Mg-Al LDH catalysts were 225, 277 and 350 °C, respectively. So, the Co-Ni LDH showed the highest activity. Furthermore, Ni-Al LDH exhibited the highest thermal stability. So, we concluded that Ni-Al LDH is a superior catalyst for toluene oxidation in the studied series. تفاصيل المقالة
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  8 - سنتز نانوکامپوزیت نیکل - مس به کمک مایکروویو برای اکسایش الکتروکاتالیزوری متانول؛ یک ماده کارآمد جهت آند برای کاربردهای پیل سوختی الکلی
  محمد علی کامیابی بابک جلیلیان
  در این مطالعه، سنتز و کاربرد نانو کامپوزیت هایی دو فلزی نیکل ‌ـ مس و کاهش گرافن اکسید بطور همزمان با استفاده از امواج مایکروویو گزارش می شود. روش سنتز پیشنهادی یک فرآیند ساده، سریع و قابل کنترل بشمار می‌رود. رفتار الکتروشیمیایی کاتالیزور سنتز شده برای واکنش اکسایش مت أکثر

  در این مطالعه، سنتز و کاربرد نانو کامپوزیت هایی دو فلزی نیکل ‌ـ مس و کاهش گرافن اکسید بطور همزمان با استفاده از امواج مایکروویو گزارش می شود. روش سنتز پیشنهادی یک فرآیند ساده، سریع و قابل کنترل بشمار می‌رود. رفتار الکتروشیمیایی کاتالیزور سنتز شده برای واکنش اکسایش متانول (MOR) در محیط قلیایی مورد بررسی قرار گرفت.. اثر ملامین بر فعالیت الکتروکاتالیستی کاتالیزور سنتز شده با روش‌های ولتامتری چرخه‌ای (CV)، کرونو آمپرومتری (CA) و طیف‌سنجی امپدانس الکتروشیمیایی (EIS) مطالعه شد. همچنین بررسی اثر ملامین به عنوان منبع نیتروژن منجر به دوپ‌شدن نیتروژن در شبکه گرافن اکسید کاهش یافته نشان داد که تا حدی منجر به تشکیل ساختارهای NiCu-N می‌شود. و این پیوند فلز-N باعث افزایش فعالیت کاتالیزوری نسبت به MOR می‌شود. اثر ترویجی ملامین با افزایش 203 میکروآمپری در جریان و کاهش 20 میلی ولتی در پتانسیل شروع در مقایسه با سایر کاتالیزورهای شاهد سنتز شده در طی فعالیت MOR ثابت شد نتایج نشان‌دهنده عملکرد عالی کاتالیزور سنتز شده بعنوان آند در پیل‌ سوختی مستقیم متانول است. تفاصيل المقالة
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  9 - Treatment of Spent Caustic Effluent of Oil Refinery with Catalytic Oxidation and Optimization of Relevant Parameters using Response Surface Methodology
  Rogayeh Elmi Amir Farshi arezoo nejaei Mohammad Ebrahim Ramazani Ebrahim Alaie
  10.22034/ap.2021.1923341.1093
  Caustic soda is a substance used for sweetening hydrocarbon products in oil refinery, gas and petrochemical units. The caustic soda-generated salts are increasingly formed during the process of removing impurities like mercaptans, sulfides and nitrates, which finally le أکثر

  Caustic soda is a substance used for sweetening hydrocarbon products in oil refinery, gas and petrochemical units. The caustic soda-generated salts are increasingly formed during the process of removing impurities like mercaptans, sulfides and nitrates, which finally leave process system through spent caustic discharge. Spent caustic discharge into environment is prohibited due to the presence of compounds like organic and toxic substances, sulfide salts, mercaptans as well as high chemical oxygen demand (COD), emphasizing the need to treat such effluents. The present study aimed to apply catalytic wet air oxidation method for treatment of spent caustic effluent from Bandar Abbas oil refinery and to optimize related parameters. Experimental processes were performed in a 500-ml batch reactor. Catalyst concentration, residence time and stoichiometric air flow parameters were optimized by Box-Behnken design. Based on the results, optimal conditions for this process were the catalyst concentration of 123 ppm, the residence time of 3 h and the stoichiometric air flow of 4.1 l/h, with a maximum reduction of spent caustic COD of 42.2%. The results of optimization experiments were analyzed by Design Expert 11 software, the results of which documented that the three mentioned parameters had the greatest effect on reducing spent caustic COD. Prolonging residence time had no significant effect on COD removal. Polynomial equation based on the three mentioned variables was presented to predict the spent caustic COD changes. In this treatment method, in addition to a significant reduction in COD, the available toxic substances also reached less than 1 ppm. تفاصيل المقالة