Pankaj A Apte

Associate Professor

  • Email

    papte[AT]iitk.ac.in

  • Office Phone No.

    +91-512-259-7457 (Office)
    +91-512-259-7457 (Lab)

  • Office & Lab

    Faculty Building 454 (Office)
    NL-II-300 (Lab)

  • Group Home Page IRINS Profile

Research Interest

  • Cooperative phenomena in phase transitions
  • Ring based mesoscale structures in tetrahedral amorphous materials
  • CO2 absorption in potassium carbonate and amine solutions with promoters
  • CO2 methanation using Alumina supported Ni3Fe as a catalyst

Education

  • B Tech, LIT, Nagpur, 1998
  • M Tech, IIT, Kanpur, 2000
  • Ph D, Ohio State University, Dec. 2005
  • Post-doc, University of Nebraska-Lincoln, 2006

Research Overview

Current research in my group is focussed on exploring the cooperative phenomena in phase transitions. When cooperativity is established, atoms or molecules in the whole system act concertedly such that the system, it its entirety, is driven in a specific direction leading to a transition. Many of the phase transitions remain poorly understood due to lack of recognition of the underlying cooperative phenomena. Recently we have shown that ordering transition in Ni3Fe alloy is caused by cooperative freezing of the L12 ordered domains at the critical temperature and the resulting propagation of the domains upon further cooling. A practical manifestation of this cooperative freezing is the critical slowing down, i.e., a significant increase in equilibration time (to 40 days or more) during annealing of Ni3Fe alloy as the critical temperature (500 ) is approached. Another important class of transitions are those responsible for formation of tetrahedral amorphous materials. We found that cooperative relaxation of the tetrahedral network transforms supercooled water into stacking disordered ice, also known as low density amorphous (or LDA) ice. A similar transition is also found in supercooled silicon that leads to formation of amorphous silicon which is commonly used in solar cells. A related research activity in my group is the investigation of structural changes in tetrahedral materials based on ring based mesostructures. We have proposed and implemented a method to identify the rings with specific shapes using puckering method which was originally developed (about five decades ago) to analyse organic ring compounds. With this method, we have been able to identify the boat and chair shaped six-membered rings. Such rings form the basis of mesostructures that are commonly found in tetrahedral materials. Using this approach, we have introduced a new method to identify hexagonal crystalline particles in amorphous materials. We have also explored ring based defect structures such as pentagonal nanochannels which, potentially, have a profound influence on the bulk properties of amorphous ice. Apart from these theoretical and computational approaches, we have also recently started experimental work to understand ionic equilibria in problems of practical interest. In particular, we are working on CO2 absorption in aqueous potassium carbonate and amine solutions with small amounts of added promoters. Such absorption processes are commonly employed in fertilizer industry. Our aim is to understand the ionic equilibria responsible for enhancement of absorption rates due to added promoters such as glycine. In collaboration with the heterogeneous catalysis group (Prof. Goutam Deo), we are also exploring the use of Alumina supported Ni3Fe as a catalyst for CO2 methanation reaction.

Awards

  • Gold Medal, B. Tech., Nagpur University (1998).
  • Outstanding graduate student award for academic achievement, OSU Department of Chemical Engineering (2005).

Publications

  • Jitendra Kumar Prabhakar, Pankaj A. Apte and Goutam Deo, Exploring optimal total metal loading of Ni3Fe/Al2O3 catalyst for CO2 methanation and its kinetic model, Fuel, 367, 131447 (2024).
  • Jitendra Kumar Prabhakar, Pankaj A. Apte and Goutam Deo, The kinetics of Ni/Al2O3 and Ni-Fe/Al2O3 catalysts for the CO2 methanation reaction and the reasons for promotion, Chemical Engineering Journal, 144252 (2023).
  • A. Mangla, G. Deo, Pankaj A. Apte, Cooperative freezing of the L12 ordered domains at the critical cooling temperature of Ni3Fe alloy", Journal of Statistical Mechanics: Theory and Experiment, 093204 (2022).
  • N. Pingua, P. A. Apte, Topological Identification Criteria, Stability, and Relevance of Pentagonal Nanochannels in Amorphous Ice", Journal of Physical Chemistry B, 123 (2019).
  • N. Pingua, P. A. Apte, Increase in local crystalline order across the limit of stability leads to cubic-hexagonal stacking in supercooled monatomic (mW) water", Journal of Chemical Physics 149, (2018).
  • A. Mangla, G. Deo, and P. A. Apte, NiFe local ordering in segregated Ni3Fe alloys: A simulation study using Angular Dependent Potential", Computational Materials Science 153C, 449 (2018).
  • A. K. Gautam, N. Pingua, A. Goyal, P. A. Apte, Dynamical instability causes the demise of a supercooled tetrahedral liquid", Journal of Statistical Physics 168, 1302 (2017).