Search or add a thesis

Advanced Search (Beta)
Home > Investigating the Activity of Zirconia As a Catalyst and As a Support for Noble Metals in Organic Oxidation Reactions

Investigating the Activity of Zirconia As a Catalyst and As a Support for Noble Metals in Organic Oxidation Reactions

Thesis Info

Access Option

External Link

Author

Sadiq, Muhammad

Program

PhD

Institute

University of Peshawar

City

Peshawar

Province

KPK

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Physical Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10127/1/Muhammad%20Sadiq_Physical%20Chem_2009_UoPsw_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676724815264

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Alcohols and cyclic alkanes oxidation, in an environment friendly protocol, was carried out in a typical batch reactor. These reactions were carried out in solvent free conditions and/or in eco-friendly solvents using molecular oxygen as the only oxidant and ZrO2 and/or ZrO2 supported noble metals (Pt, Pd) as catalysts. The influence of different reaction parameters (speed of agitation, reaction time, and temperature), catalyst parameters (calcination temperature and loading), and oxygen partial pressure on the catalyst performance was studied. Different modern techniques such as (FT-IR, XRD, SEM, EDX, surface and pores size analyzer and particle size analyzer) were used for the characterization of catalyst. ZrO2 calcined at 1223 K was found to be more active as a single catalyst than the one calcined at 723 K for alcohol oxidation to the corresponding carbonyl products under solvent free conditions and in ecofriendly solvent as well. Platinum supported on zirconia was highly active and selective for oxidation of benzyl alcohol to benzaldehyde in n- heptane, and toluene to benzoic acid in both solvent free conditions and in aqueous medium. Similarly, zirconia supported Pt or Pd catalysts were tested for cyclohexane oxidation in solvent free conditions and for phenol oxidation in aqueous medium. Both catalysts have shown magnificent catalytic activity. Bismuth was added as a promoter to these catalysts. Bismuth promoted Pt/ZrO2 has shown outstanding catalytic performance. These catalysts are insoluble in the reaction mixture and can be easily separated by simple filtration and reused. Typical batch reactor’s kinetic data were obtained and fitted to the classical Langmuir–Hinshelwood, Mars–van Krevelen and as well as to the Eley-Rideal model of heterogeneously catalyzed reactions. In alcohol oxidation reactions the Langmuir-Hinshelwood model was found to give a better fit. The rate-determining step was proposed to involve direct interaction of an adsorbed oxidizing species with the adsorbed reactant or an intermediate product of the reactant. While in toluene oxidation the Eley-Rideal model was found to give a better fit. Eley-Rideal mechanism envisages reaction between adsorbed oxygen with hydrocarbon molecules from the fluid phase. The calculated apparent activation energy and agitation effect have shown the absence of mass transfer effect.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

حکیم صدیق احمد امروہوی بریلوی

حکیم صدیق احمد امروہوی ثم بریلوی
مئی کے اسی ہفتہ میں ایک اورحادثہ یہ پیش آیا کہ ہمارے نہایت عزیز اور مخلص دوست اوراپنے فن کے ماہرحکیم صدیق احمد صاحب امروہوی ثم بریلوی نے وفات پائی۔عمرغالباًپچھتر چھہتر برس ہوگی۔اصل وطن امروہہ ضلع مرادآباد تھا، مگر ایک عرصۂ دراز سے بریلی میں مقیم تھے۔ ان کے والد ماجد مولانا حکیم مختار احمد صاحب ایک نہایت حاذق طبیب ہونے کے علاوہ پختہ استعداد کے عالم باعمل، متقی اور عابد و زاہد بزر گ تھے۔ حکیم صدیق احمد کی بھی علوم وفنون میں استعداد بڑی پختہ تھی، شروع میں منطق اورفلسفہ کا بڑاغلبہ رہا۔نہایت ذہین اور طباع تھے۔اس لیے کوئی موضوع بحث ہو تقریر مدلل اورمنطقیانہ کرتے تھے۔ حضرت شاہ عبدالقادر صاحب رائے پوری سے بیعت ہونے کے علاوہ اعمال و وظائف کا ورد کثرت سے کرنے لگے تھے۔فن طب میں نظری اورعملی مہارت و حذاقت انھیں ورثہ میں ملی تھی، طبیعت بے حد رساتھی۔تشخیص اورتجویز دونوں میں ان کی شہرت دور دور تک تھی۔ سینکڑوں بڑے معرکے کے علاج کئے لیکن وہ جتنے بڑے طبیب تھے، اسی قدر مزاج سخت لاابالی اورروپیہ پیسہ کے لالچ سے کوسوں دورتھے۔ غریبوں اور ضرورت مندوں کی امداد اپنی جیب سے کرتے تھے اورعلما کی خدمت کرکے خوش ہوتے تھے، غرض کہ بڑی خوبیوں اورکمالات کے انسان تھے۔اُن کے پاس مخطوطات کاایک خاصہ ذخیرہ تھا جس میں حضرت مولانا محمد قاسم صاحب نانوتوی اوربعض دوسرے بزرگوں کے مکاتیب اور ان کی تحریریں شامل ہیں۔لیکن راقم الحروف کے سخت اصرار کے باوجود انھوں نے ان چیزوں کو نہ خود چھاپا اورنہ کسی اورکو انھیں نقل کرنے کی اجازت دی۔پھر معلوم نہیں ان کا کیا حشر ہوا۔
اخلاق وعادات کے اعتبار سے نہایت خلیق،خوش طبع و خوش مزاج اور متواضع و مہمان نواز تھے۔رحمہ اﷲ رحمۃً واسعۃً۔ [جون۱۹۷۸ء]

Technical Terms Used in General English Textbooks Across Disciplines

The study aimed to analyze lexical items underpinned in the textbooks used in the current teaching of ESP and GE. Using content analysis, a systematic evaluation of texts to examine nuances to bridge the gap between quantitative and qualitative data. This was such of importance, however, difficult to study due to issues of interest like in the study, frequency of lexical items in ESP, and GE textbooks. Results found 13,713 lexical items in Hospitality Management, 17,561 in Criminology, 4576 in Tourism, 7167 in Marine Engineering, and 512 in Information Technology. Furthermore, the overall percentage of ESP lexical items fell in Tier 2 (with multiple-meaning while the least was in Tier 3, specifically on context-specific vocabulary. It is the core of vocabulary learning to ensure English language teaching. It is its goal to help learners better understand language, allowing them to understand others as they want to express themselves as well. This applies not only in speaking but also in writing and reading. Wilkins (1972, p. 111-112) stated that without grammar very little understanding can be acquired and without vocabulary there can be no learning at all. Thus, even without good grammar, so long as you equipped with useful words and expression, one can still manage to communicate. Lewis (1993) argued that “lexis is the heart of language” and that it develops a better fluency and expression in English. He also added the significance to the learners of acquiring a more productive vocabulary knowledge, also, their eagerness to develop their own personal vocabulary strategies. Thus, a proposed bridge model program was recommended to highlight the study findings using the lexicons found from the different respective courses.

The Classification of Multispectral and Statistical Texture Data Using Data Mining Techniques

The real-time information for land use/land cover (LU/LC) data is very important for resource management, future prediction, and crops growth assessment. Although conventionally LU/LC data is collected through field survey but remote sensing data collection has its own importance due to time, accuracy and transparency factors. During the last decade, advancement in spaceborne multispectral data has proven to be beneficial over airborne data for land monitoring due to their increased spectral resolution. The objective of this research is to compare and analyze the five types (Fertile, Green pasture, Desert-rangeland, Bare and Sutlej-river land) of LU/LC multispectral data (five bands) acquired by multispectral radiometer (MSR5) and digital photographic data acquired from high resolution 10.1 megapixel Nikon camera. All experimentation has been performed using MaZda software version 4.6 with WEKA data mining tool version 3.6.12 on Intel® Core i3 processor 2.4 gigahertz (GHz) with the the 64-bit operating system. This research is conducted at The Islamia University of Bahawalpur province Punjab (Pakistan), located at 29°23′44″N and 71°41′1″E. For photographic data, image pre-processing techniques are applied, i.e., grayscale conversion, enhanced the contrast and sharpening procedure. Extract the 229 statistical texture features of the LU/LC data of each 512×512 image size. Three feature selection techniques fisher (F), the probability of error plus average correlation coefficient (POE+ACC) and mutual information (MI) are combined together (F+PA+M) and extract thirty most discriminant features out of 229 features space of each photographic image. For feature reduction, non-linear discriminant analysis (NDA) for photographic data (texture data) and linear discriminant analysis (LDA) for remote sensing data (multispectral data) have shown better clustering as compared to principal component analysis (PCA) and raw data analysis (RDA). Finally, we have employed different data mining classifiers namely, Artificial Neural Network (ANN), Random Forest (RF), Naive Bayes (NB) and J48 for classification. It is observed that artificial neural network (ANN: n class) is applied for training and testing by cross-validation (80-20) on these texture and multispectral data. It showed comparative better 91.332% accuracy for texture dataset and 96.40% for multispectral (MSR5) dataset respectively among all the employed classifiers.