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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.

Abstract Single atoms of platinum group metals on CeO2 represent a potential approach to lower precious metal requirements for automobile exhaust treatment catalysts. Here we show the dynamic evolution of two types of single-atom Pt (Pt1) on CeO2, i.e., adsorbed Pt1 in Pt/CeO2 and square planar Pt1 in PtATCeO2, fabricated at 500 °C and by atom-trapping method at 800 °C, respectively. Adsorbed Pt1 in Pt/CeO2 is mobile with the in situ formation of few-atom Pt clusters during CO oxidation, contributing to high reactivity with near-zero reaction order in CO. In contrast, square planar Pt1 in PtATCeO2 is strongly anchored to the support during CO oxidation leading to relatively low reactivity with a positive reaction order in CO. Reduction of both Pt/CeO2 and PtATCeO2 in CO transforms Pt1 to Pt nanoparticles. However, both catalysts retain the memory of their initial Pt1 state after reoxidative treatments, which illustrates the importance of the initial single-atom structure in practical applications.

While university change initiatives have become more common in the face of changing learner needs and higher education funding, many fail to produce desired effects, even when guided by organizational change models. The purpose of this study was to document a successful change process in an engineering department at a Hispanic-serving institution in the southwestern United States. The change effort focused on enhancing faculty capacity to support diverse student success. The change process was planned using Kotter's eight-step change model (1996) and was therefore a prescribed, linear, sequential change process. Qualitative analysis of audio-recorded faculty interviews and meetings, artifacts, field notes, and participant observation highlights how Kotter's change model was implemented iteratively and emergently. Early steps were revisited and strategies were treated as improvable. This approach enhanced faculty buy-in and project success. Characterization of each step provides insight into ways to apply Kotter's change model in higher education settings.

Lower division chemistry and chemical engineering courses commonly emphasize efficient acquisition of core content. While experts perceive the organization of the discipline, students perceive their courses as fragmented. This has a more severe impact on students from groups historically excluded from STEM fields, who may not have a deep understanding of the opportunities that lie on the horizon. In order to make progress on this issue, we first sought to better understand our diverse students' chemical engineering funds of knowledge that is, the everyday and cultural experiences salient for chemistry and chemical engineering. We found that minoritized students expressed more funds of knowledge: women expressed STEM interest and past success more than men; students from minoritized racial and ethnic groups and/or who spoke a language other than English at home expressed more community funds of knowledge. We developed design challenges for core chemical engineering courses to build on these varied funds of knowledge. We found no differences between minoritized students and their more privileged peers in terms of their intent to persist. We share implications for both chemistry and chemical engineering courses seeking to support diverse student success.

India is the major producer of Areca nut in the world. Volatile demand and price are the major challenges for the Areca nut growers in India. The use of time series models to manage the price risk has become the interest of academicians today. This paper deals with developing an appropriate model to predict the prices of a new variety of Areca nut in Karnataka using monthly price data for the period January 2009 to December 2018. Box Jenkins ARIMA methodology is used to develop the model. Along with ARIMA estimates, log-likelihood, Akaike’s information criterion (AIC) and Bayesian (BIC) information criterion statistics are also estimated to decide on the appropriate model. ACF and PACF correlograms for residuals of ARIMA are used to do the diagnostic check of the selected ARIMA model. Appropriate model to forecast the new variety Areca nut price is ARIMA (3, 1, 3)

During the past decade, initial skepticism rapidly changed into widespread recognition of the role of single atoms in heterogeneous catalysts. The next decade could usher in the era of industrial applications as manufacturing of durable single atom catalysts is perfected.

While single-atom catalysts (SACs) have attracted a lot of interest, the nature of the active sites in SACs remains elusive. Here the authors elucidate that depositing single atoms via high temperature synthesis leads to improved reducibility of lattice oxygen on CeO2 yielding low temperature reactivity of Pt catalysts in CO oxidation.

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]