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Engineering is fundamentally about design, yet many undergraduate programs offer limited opportunities for students to learn to design. This design case reports on a grant-funded effort to revolutionize how chemical engineering is taught. Prior to this effort, our chemical engineering program was like many, offering core courses primarily taught through lectures and problem sets. While some faculty referenced examples, students had few opportunities to construct and apply what they were learning. Spearheaded by a team that included the department chair, a learning scientist, a teaching-intensive faculty member, and faculty heavily engaged with the undergraduate program, we developed and implemented design challenges in core chemical engineering courses. We began by co-designing with students and faculty, initially focusing on the first two chemical engineering courses students take. We then developed templates and strategies that supported other faculty-student teams to expand the approach into more courses. Across seven years of data collection and iterative refinements, we developed a framework that offers guidance as we continue to support new faculty in threading design challenges through core content-focused courses. We share insights from our process that supported us in navigating through challenging questions and concerns.

Abstract Identification of active sites in catalytic materials is important and helps establish approaches to the precise design of catalysts for achieving high reactivity. Generally, active sites of conventional heterogeneous catalysts can be single atom, nanoparticle or a metal/oxide interface. Herein, we report that metal/oxide reverse interfaces can also be active sites which are created from the coordinated migration of metal and oxide atoms. As an example, a Pd1/CeO2 single-atom catalyst prepared via atom trapping, which is otherwise inactive at 30 °C, is able to completely oxidize formaldehyde after steam treatment. The enhanced reactivity is due to the formation of a Ce2O3-Pd nanoparticle domain interface, which is generated by the migration of both Ce and Pd atoms on the atom-trapped Pd1/CeO2 catalyst during steam treatment. We show that the generation of metal oxide-metal interfaces can be achieved in other heterogeneous catalysts due to the coordinated mobility of metal and oxide atoms, demonstrating the formation of a new active interface when using metal single-atom material as catalyst precursor.

The local structure of the metal single-atom site is closely related to the catalytic activity of metal single-atom catalysts (SACs). However, constructing SACs with homogeneous metal active sites is a challenge due to the surface heterogeneity of the conventional support. Herein, we prepared two Rh1/CeO2 SACs (0.5Rh1/r-CeO2 and 0.5Rh1/c-CeO2, respectively) using two shaped CeO2 (rod and cube) exposing different facets, i.e., CeO2 (111) and CeO2 (100). In CO oxidation reaction, the T100 of 0.5Rh1/r-CeO2 SACs is 120 °C, while the T100 of 0.5Rh1/c-CeO2 SACs is as high as 200 °C. Via in-situ CO diffuse reflectance infrared Fourier transform spectroscopy (CO-DRIFTS), we found that the proximity between OH group and Rh single atom on the plane surface plays an important role in the catalytic activity of Rh1/CeO2 SAC system in CO oxidation. The Rh single atom trapped at the CeO2 (111) crystal surface forms the Rh1(OH)adjacent species, which is not found on the CeO2 (100) crystal surface at room temperature. Furthermore, during CO oxidation, the OH group far from Rh single atom on the 0.5Rh1/c-CeO2 disappears and forms Rh1(OH)adjacent species when the temperature is above 150 °C. The formation of Rh1(OH)adjacentCO intermediate in the reaction is pivotal for the excellent catalytic activity, which explains the difference in the catalytic activity of Rh single atoms on two different CeO2 planes. The formed Rh1(OH)adjacent-O-Ce structure exhibits good stability in the reducing atmosphere, maintaining the Rh atomic dispersion after CO oxidation even when pre-reduced at high temperature of 500 °C. Density functional theory (DFT) calculations validate the unique activity and reaction path of the intermediate Rh1(OH)adjacentCO species formed. This work demonstrates that the proximity between metal single atom and hydroxyl can determine the formation of active intermediates to affect the catalytic performances in catalysis. [ABSTRACT FROM AUTHOR]

In this work, we have described the synthesis of vanadium (V) nanoparticles (NPs) anchored on mesoporous graphitic carbon nitride (V@mpg-C 3 N 4 ) and their uses in photocatalytic ethylbenzene oxidation to the respective acetophenones. The mpg-C 3 N 4 serves as the support for the decoration of V NPs, through a simple impregnation method. Various advanced techniques, such as XRD, UV-vis spectrometry, HRTEM, HAADF-STEM, AC-STEM, elemental mapping, and BET surface area analysis, were employed for the characterization of V@mpg-C 3 N 4 . The detailed characterization studies reveal that the V@mpg-C 3 N 4 catalyst has a medium band gap (2.78 eV), a high surface area (76.7 m 2 g -1 ), and a mesoporous nature. The V@mpg-C 3 N 4 photocatalysts demonstrated excellent performance in the light-assisted oxidation of ethylbenzene, achieving over 99 % conversion and selectivity for acetophenone in an environmentally friendly solvent (water) using a domestic light source (50 W white light). This developed synthesis strategy will be useful for synthesizing various noble and non-noble metal-based catalysts and their applications in organic transformation and environmental remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)