The Department of Chemical Engineering at Al-Nahrain University held a discussion for PhD student Alaa Jassim Awadh regarding his thesis titled:

"Synthesis and Catalytic Isomerization Activity of Bifunctional Supported Pt-Heteropolyacid Nanocatalyst" The discussion committee, which took place in Al-Furat Hall / College of Engineering on Wednesday, October 30, 2024, consisted of the following members and their affiliations:

1. Prof. Dr. Khalid Ajami Sukkar - College of Engineering / University of Technology - Chair

2. Prof. Dr. Mohammed Dakhil Salman - College of Engineering / University of Dhi Qar - Member

3. Assoc. Prof. Dr. Yasser Imad Abdul Aziz - College of Engineering / Al-Nahrain University - Member

4. Assoc. Prof. Dr. Sarmad Talib Najm - College of Engineering / Al-Nahrain University - Member

5. Assoc. Prof. Dr. Haidar Mufaq Tofiq - College of Engineering / Al-Nahrain University - Member

6. Prof. Dr. Saad Hanish Ammar - College of Engineering / Al-Nahrain University - Supervisor

The thesis was scientifically evaluated by the first scientific reviewer, Prof. Dr. Ammar Saleh Abbas from the University of Baghdad, College of Engineering, and the second scientific reviewer, Prof. Dr. Hamid Hussein Alwan from the University of Babylon, College of Engineering, and linguistically reviewer by Assoc. Prof. Dr. Ahmed Farhan Muwaiz from the College of Engineering, Al-Nahrain University.

In the current work, effective bifunctional nanocatalyst systems composed of Pt and Keggin heteropolyacid, namely tungstophosphoric acid (TPA) loaded onto different supporting metal oxides including Nb2O5, Al2O3, and TiO2 (Pt/TPA/Nb2O5, Pt/TPA/Al2O3, and Pt/TPA/TiO2) were constructed for catalytic isomerization of n-hexane. The synthesized catalysts were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), filed emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherms, and thermogravimetric analysis (TGA). The n-hexane isomerization experiments were conducted over synthesized catalysts at different reaction temperatures (Tem. = 120−200 °C), liquid hourly space velocities (LHSV = 1 – 3 h-1) and H2:n-hexane molar ratios (H2/HC = 0.5 – 1.5). 

The response surface methodology (RSM) designed by Box-Behnken Design (BBD) was used to optimize the catalytic isomerization. Statistical analysis of experimental data was accomplished to generate the second-order polynomial model. 

The results showed that the 1 wt% Pt-30 wt% TPA supported catalysts have successful structural properties, high surface area, high acidity, and uniform distribution of Pt nanoparticles on their surfaces as demonstrated by XRD, BET surface area, FTIR, and TEM studies, which was supportive to achieve highly catalytic isomerization activities. Pt/TPA/Nb2O5 catalyst sample possesses the highest isomerization efficiency (51%) compared with 40.2% and 41% for Pt/TPA/TiO2 and Pt/TPA/Al2O3, respectively.

The high isomerization conversion and selectivity were achieved chiefly due to the highly dispersed Pt nanoparticles, appropriate acidity provided by Keggin PWA heteropolyacid with a balanced Bronsted/ Lewis acid sites ratio, and highly ordered large mesopores. The most significant finding in this work is that the mesopore structure has large pore sizes, proper acidity, and highly dispersed supported nanoparticles