Carbon-doped Metal Oxide Interfacial Nanofilms for Precise Separation of Molecules
Sustainable energy, environment, water (H2O), and food, to some extent, depends on acquiring/capturing/utilizing small molecules, such as H2O, ammonia (NH3), carbon dioxide (CO2), methane (CH4), ethanol, and liquid hydrocarbons, etc. Precisely designing stable, molecular-scale pores for sieving these molecules, either from the final product or during their production processes, could be an effective way of separating these molecules or promoting their production using compact and well-engineered systems. Considering the very small sizes (0.26-1.0 nm) of these molecules and tiny size difference from their contaminants/by-products, it is a grand challenge to design these molecular-scale pores. My research interest is focused on rationally designing and preparing advanced nanoporous structures for precisely distinguishing molecules by size/shape differences, characterizing and understanding the nanostructures, and applying them for separation and catalysis. In this talk, I will first give an overview of my research work and then present our recent research work on Carbon-doped Metal Oxide Interfacial Nanofilms for Precise Separation of Molecules.
Materials with rigid, precisely controlled nanopores that are within 1 nm and stable in harsh conditions have potential to be fabricated into membranes for organic solvent nanofiltration (OSN). To achieve high permeance through these membranes, the traditional route is to reduce the selective layer thickness and thus lower the transport resistance. Although membranes as thin as one atom have been prepared, this thinness often challenges the membrane’s potential for defect free scale-up. Another route, often overlooked, is to increase the pore interconnectivity of the membrane material, described by the ratio of porosity and tortuosity (õ/ÃÂ), which greatly influences the transport through a membrane. In this work, we fabricated membranes using a hybrid nanofilm with highly interconnected pores, with õ/àof ~ 0.2, almost doubling that of the current OSN membranes, and obtained methanol permeance as high as 267 L m-2 h-1 bar-1, > 2.5 times higher than the reported membranes with similar molecular weight cut-off (MWCO). Precise tuning of MWCO in the range of 200-1,000 Da with a step change as small as approximately 100 Da was realized by adjusting the membrane synthesis and calcination conditions. Molecular dynamics (MD) simulation shows the formation of nanometer-sized pores in hybrid material, while pore size and interconnectivity were realized as a function of the calcination conditions. These membranes have rigid pores that are stable in various organic solvents and at elevated temperatures, ensuring stable molecular separation under challenging industrial conditions.
Bio: Miao Yu joined the Department of Chemical and Biological Engineering at the University at Buffalo, the State University of New York, as an Empire Innovation Professor in January 2021. He was an associate professor in the Department of Chemical and Biological Engineering at Rensselaer Polytechnic Institute from August 2017 to January 2021. Before joining RPI, he was an assistant professor in the Department of Chemical Engineering at the University of South Carolina between 2012 and 2017. He was an assistant research professor in the Department of Chemical and Biological Engineering at the University of Colorado, Boulder from 2010 to 2012. He obtained B.S. (1998) and M.S. (2002) degrees from Tianjin University, China. He earned his Ph.D. from CU-Boulder in 2007 and subsequently worked in the same department as a postdoctoral researcher from 2007 to 2010. Yu has published more than 100 peer-reviewed papers; four of them were published in Science, and others in Nature Communications, Advanced Materials, JACS, Nano Letters, Angewandte Chemie International Edition, ACS Catalysis, Chemical Communications, etc. He is the recipient of 2015 NSF Career Award and 2022 AIChE Separations Division FRI/Yeoman Innovation Award.