Preparation and characterization of nanocrystalline NiO by the thermal decomposition of oxalate salts for the dehydrogenation of 2-butanol to methyl ethyl ketone

abouelhassan gomaa,adel abdelkader,samih halawy

doi:10.21608/aujes.2021.77260.1025

abouelhassan gomaa, adel abdelkader + Show 1 more

Open Access

https://doi.org/10.21608/aujes.2021.77260.1025

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Abstract

In the present study, highly active nanocrystalline nickel oxide samples were prepared by using a simple, solvent-free, and cost-effective preparation method. Commercial nickel oxalate dihydrate powder was mixed with deionized water to form a soft paste which was sonicated till dryness and then, calcined in static air. The prepared nickel oxide samples were characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 adsorption-desorption techniques. The surface basicity of the prepared oxide samples was measured by adsorption of CO2 molecules followed by desorption measurements using the thermogravimetry (TG) technique. The catalytic activity of the prepared nickel oxide samples towards the dehydrogenation of 2-butanol to methyl ethyl ketone (MEK) was studied at a temperature range of 225-325°C. The effects of calcination temperature, reaction temperature, and weight hourly space velocity WHSV on the catalytic activity were studied to determine the best calcination temperature and the optimum operating conditions. The sample calcined at 400°C showed the highest activity and the optimum operating conditions were found to be at the reaction temperature of 300°C and WHSV of 15 L h-1 g-1. The selectivity to MEK was higher than 85% for all the conducted experiments.

Highlights

Nickel oxide (NiO) is a ferromagnetic crystalline solid material with unique magnetic, electrical, and optical properties that make it the main subject of a large number of research studies )Zhao et al, 2016
The thermal analyzer is equipped with a data acquisition and handling system (TA-50WSI), while α-alumina was used as the reference material in (DTA) measurements
The effect of calcination temperatures of NiO catalysts on their catalytic activity is clear from the notable decrease in the % conversion by increasing the calcination temperature as shown in Figure 5 where the order of catalytic activity is N400 > N500 ≈ N600

Summary

Preparation of NiO samples

Nickel oxalate dihydrtae NiC2O4.2H2O powder was mixed with a little amount of de ionized water using ultrasonic bath at 70 °C to obtain a homogeneous paste which was left in the ultrasonic bath till dryness. Characterization of NiO samples Thermogravimetry (TG), and differnitial thermal analysis (DTA) were performed at heating rate 10°C/min in a flow of 40 cm3/min dry nitrogen, using automatically recording model 50H Shimadzu thermal analyzer, Japan. The thermal analyzer is equipped with a data acquisition and handling system (TA-50WSI), while α-alumina was used as the reference material in (DTA) measurements. The BET surface area measurements were performed at liquid nitrogen temperature (-195°C) using an automatic Gemini VӀӀ Micromeritics (USA) Model 2390P in Egyption ferroalloys company. Catalytic activity measurements The catalytic activity of all the catalysts for the vapor phase dehydrogenation/dehydration of 2-butanol as indicated in scheme.. All catalysts were subjected to the reaction at saturator temperature 5 °C and weight hourly space velocity equal 30 Lh-1g-1 which give (100 ml/min = 0.789% secondary butanol + 99.211% nitrogen).

AND DISCUSSION

Findings

Conclusion