- Post Doctoral
MIT Unit Affiliation:
- Chemical Engineering
Post Doc Sponsor / Advisor:
Date PhD Completed:
Top 3 Areas of Expertise:
My name is Dr. Andrew Teixeira, and I am seeking employment as an Assistant Professor in a tenure-track position. I am currently completing my second year as a Postdoctoral Associate at the Massachusetts Institute of Technology (MIT) where I have been developing microfluidics as a tool to uncover rapid kinetics/catalysis in multiphase flow with Professor Klavs Jensen. I completed my Ph.D. in Chemical Engineering in August of 2014 under the direction of Professor Paul Dauenhauer (now at the University of Minnesota) studying biomass fast pyrolysis and surface structured barriers in hierarchical zeolites at the University of Massachusetts Amherst (UMass).
My professional drive is to pursue an understanding of complex systems in highly relevant research frontiers by implementing a core experimental approach that bridges the fields of chemical engineering, materials science, and electrical engineering. Applicable to renewable chemicals/clean energy (metal catalysis, zeolites, biofuels) and pharmaceutics (enantomeric crystallization, flow chemistry), my future research will reveal entirely unexplored pathways for catalytic reactions (N2 fixation), kinetic surface studies, and crystallization.
Expected End Date of Post Doctoral Position:
During my Ph.D. I extensively studied the extreme conditions of biomass fast pyrolysis (T > 500 °C, τ ~ 1 ms) leading to new core understandings of the mechanisms for woody biomass conversion via the reactive liquid melt phase. In parallel, I applied a kinetic approach to reveal asymetric structural surface barriers in hierarchical zeolites that cause as many as three orders of magnitude diminishment in transport rates. At MIT, I developed a sub-milligram analysis techniques for heterogeneous catalysts characterization, and performed flow-based kinetic measurements of amino acid activation for automated peptide synthesis. Of 10 publications, selected first author papers include Nature Scientific Reports, Chemistry Materials, Energy & Environmental Science, Lab on a Chip, and a highlighted article in the Editor’s Choice section of Science Magazine.
Biomass pyrolysis has been widely explored for its potential to generate a sustainable chemical source capable of producing synthetic fuels and chemicals. Lignocellulosic biomass is the carbon rich, inedible fraction of wood that is comprised of long oxygenated biopolymers, primarily cellulose, hemicellulose and the highly aromatic lignin. High temperature thermal conversion of biomass to bio-oil (pyrolysis oil) occurs on the order of milliseconds and converts long chain biopolymers to a carbon-rich liquid crude. The chemistry of biomass pyrolysis is greatly complicated by significant heat and mass transport challenges. The complex fluid dynamics of the reactive liquid intermediate are examined in situ with high temperature spatiotemporally resolved techniques (T = 450 – 1000 °C, 1 µm, 1 ms), chemical analyses and computational fluid dynamics. Discoveries include the mechanism for aerosol generation during pyrolysis, existence and control of the Leidenfrost effect, and understanding bio-oil microexplosions.
Zeolites are widely utilized to catalytically upgrade fuels by cracking, hydrogenation and hydrodeoxegenation as well as having applications in separations, sorption, ion-exchange. While new hierarchical materials are synthesized with transport lengthscales that are increasingly smaller, substantial diffusional transport limitations persist in small particles, often dominating the observed rates. The presence of these transport limitations remains a significant technical ix challenge. In this work, a mechanistic understanding is developed to describe such limitations. The potential for surface barriers to diffusion are experimentally assessed by Zero Length Chromatography and frequency response methods, and further confirmed by dynamic Monte Carlo simulations.
5 Recent Papers:
A. R. Teixeira, X. Qi, W. C. Conner, T. J. Mountziaris, W. Fan and P. J. Dauenhauer (2015). "2D Surface Structures in Small Zeolite MFI Crystals." Chemistry of Materials 27(13): 4650-4660
A. R. Teixeira, C. Krumm, K. P. Vinter, A. D. Paulsen, C. Zhu, S. Maduskar, K. E. Joseph, K. Greco, M. Stelatto, E. Davis, B. Vincent, R. Hermann, W. Suszynski, L. D. Schmidt, W. Fan, J. P. Rothstein and P. J. Dauenhauer (2015). "Reactive Liftoff of Crystalline Cellulose Particles." Nature Scientific Reports 5: 11238.
A. R. Teixeira, X. Qi, C.-C. Chang, W. Fan, W. C. Conner and P. J. Dauenhauer (2014). "On Asymmetric Surface Barriers in MFI Zeolites Revealed by Frequency Response." The Journal of Physical Chemistry C 118(38): 22166-22180.
A. R. Teixeira, C.-C. Chang, T. Coogan, R. Kendall, W. Fan and P. J. Dauenhauer (2013). "Dominance of Surface Barriers in Molecular Transport through Silicalite-1." The Journal of Physical Chemistry C 117(48): 25545-25555.
A. R. Teixeira, K. G. Mooney, J. S. Kruger, C. L. Williams, W. J. Suszynski, L. D. Schmidt, D. P. Schmidt and P. J. Dauenhauer (2011). "Aerosol generation by reactive boiling ejection of molten cellulose." Energy & Environmental Science 4(10): 4306-4321.