Matching Items (7)
Filtering by
- All Subjects: Environmental Education
- Creators: School of Sustainability
- Status: Published
Description
This honors thesis is focused on two separate catalysis projects conducted under the mentorship of Dr. Javier Pérez-Ramírez at ETH Zürich. The first project explored ethylene oxychlorination over supported europium oxychloride catalysts. The second project investigated alkyne semihydrogenation over nickel phosphide catalysts. This work is the subject of a publication of which I am a co-author, as cited below.
Project 1 Abstract: Ethylene Oxychlorination
The current two-step process for the industrial process of vinyl chloride production involves CuCl2 catalyzed ethylene oxychlorination to ethylene dichloride followed by thermal cracking of the latter to vinyl chloride. To date, no industrial application of a one-step process is available. To close this gap, this work evaluates a wide range of self-prepared supported CeO2 and EuOCl catalysts for one-step production of vinyl chloride from ethylene in a fixed-bed reactor at 623 773 K and 1 bar using feed ratios of C2H4:HCl:O2:Ar:He = 3:3 6:1.5 6:3:82 89.5. Among all studied systems, CeO2/ZrO2 and CeO2/Zeolite MS show the highest activity but suffer from severe combustion of ethylene, forming COx, while 20 wt.% EuOCl/γ-Al2O3 leads to the best vinyl chloride selectivity of 87% at 15.6% C2H4 conversion with complete suppression of CO2 formation and only 4% selectivity to CO conversion for over 100 h on stream. Characterization by XRD and EDX mapping reveals that much of the Eu is present in non-active phases such as Al2Eu or EuAl4, indicating that alternative synthesis methods could be employed to better utilize the metal. A linear relationship between conversion and metal loading is found for this catalyst, indicating that always part of the used Eu is available as EuOCl, while the rest forms inactive europium aluminate species. Zeolite-supported EuOCl slightly outperforms EuOCl/γ Al2O3 in terms of total yield, but is prone to significant coking and is unstable. Even though a lot of Eu seems locked in inactive species on EuOCl/γ Al2O3, these results indicate possible savings of nearly 16,000 USD per kg of catalyst compared to a bulk EuOCl catalyst. These very promising findings constitute a crucial step for process intensification of polyvinyl chloride production and exploring the potential of supported EuOCl catalysts in industrially-relevant reactions.
Project 2 Abstract: Alkyne Semihydrogenation
Despite strongly suffering from poor noble metal utilization and a highly toxic selectivity modifier (Pb), the archetypal catalyst applied for the three-phase alkyne semihydrogenation, the Pb-doped Pd/CaCO3 (Lindlar catalyst), is still being utilized at industrial level. Inspired by the very recent strategies involving the modification of Pd with p-block elements (i.e., S), this work extrapolates the concept by preparing crystalline metal phosphides with controlled stoichiometry. To develop an affordable and environmentally-friendly alternative to traditional hydrogenation catalysts, nickel, a metal belonging to the same group as Pd and capable of splitting molecular hydrogen has been selected. Herein, a simple two-step synthesis procedure involving nontoxic precursors was used to synthesize bulk nickel phosphides with different stoichiometries (Ni2P, Ni5P4, and Ni12P5) by controlling the P:Ni ratios. To uncover structural and surface features, this catalyst family is characterized with an array of methods including X-ray diffraction (XRD), 31P magic-angle nuclear magnetic resonance (MAS-NMR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Bulk-sensitive techniques prove the successful preparation of pure phases while XPS analysis unravels the facile passivation occurring at the NixPy surface that persists even after reductive treatment. To assess the characteristic surface fingerprints of these materials, Ar sputtering was carried out at different penetration depths, reveling the presence of Ni+ and P-species. Continuous-flow three-phase hydrogenations of short-chain acetylenic compounds display that the oxidized layer covering the surface is reduced under reaction conditions, as evidenced by the induction period before reaching the steady state performance. To assess the impact of the phosphidation treatment on catalytic performance, the catalysts were benchmarked against a commercial Ni/SiO2-Al2O3 sample. While Ni/SiO2-Al2O3 presents very low selectivity to the alkene (the selectivity is about 10% at full conversion) attributed to the well-known tendency of naked nickel nanoparticles to form hydrides, the performance of nickel phosphides is highly selective and independent of P:Ni ratio. In line with previous findings on PdxS, kinetic tests indicate the occurrence of a dual-site mechanism where the alkyne and hydrogen do not compete for the same site.
This work is the subject of a publication of which I am a co-author, as cited below.
D. Albani; K. Karajovic; B. Tata; Q. Li; S. Mitchell; N. López; J. Pérez-Ramírez. Ensemble Design in Nickel Phosphide Catalysts for Alkyne Semi-Hydrogenation. ChemCatChem 2019. doi.org/10.1002/cctc.201801430
Project 1 Abstract: Ethylene Oxychlorination
The current two-step process for the industrial process of vinyl chloride production involves CuCl2 catalyzed ethylene oxychlorination to ethylene dichloride followed by thermal cracking of the latter to vinyl chloride. To date, no industrial application of a one-step process is available. To close this gap, this work evaluates a wide range of self-prepared supported CeO2 and EuOCl catalysts for one-step production of vinyl chloride from ethylene in a fixed-bed reactor at 623 773 K and 1 bar using feed ratios of C2H4:HCl:O2:Ar:He = 3:3 6:1.5 6:3:82 89.5. Among all studied systems, CeO2/ZrO2 and CeO2/Zeolite MS show the highest activity but suffer from severe combustion of ethylene, forming COx, while 20 wt.% EuOCl/γ-Al2O3 leads to the best vinyl chloride selectivity of 87% at 15.6% C2H4 conversion with complete suppression of CO2 formation and only 4% selectivity to CO conversion for over 100 h on stream. Characterization by XRD and EDX mapping reveals that much of the Eu is present in non-active phases such as Al2Eu or EuAl4, indicating that alternative synthesis methods could be employed to better utilize the metal. A linear relationship between conversion and metal loading is found for this catalyst, indicating that always part of the used Eu is available as EuOCl, while the rest forms inactive europium aluminate species. Zeolite-supported EuOCl slightly outperforms EuOCl/γ Al2O3 in terms of total yield, but is prone to significant coking and is unstable. Even though a lot of Eu seems locked in inactive species on EuOCl/γ Al2O3, these results indicate possible savings of nearly 16,000 USD per kg of catalyst compared to a bulk EuOCl catalyst. These very promising findings constitute a crucial step for process intensification of polyvinyl chloride production and exploring the potential of supported EuOCl catalysts in industrially-relevant reactions.
Project 2 Abstract: Alkyne Semihydrogenation
Despite strongly suffering from poor noble metal utilization and a highly toxic selectivity modifier (Pb), the archetypal catalyst applied for the three-phase alkyne semihydrogenation, the Pb-doped Pd/CaCO3 (Lindlar catalyst), is still being utilized at industrial level. Inspired by the very recent strategies involving the modification of Pd with p-block elements (i.e., S), this work extrapolates the concept by preparing crystalline metal phosphides with controlled stoichiometry. To develop an affordable and environmentally-friendly alternative to traditional hydrogenation catalysts, nickel, a metal belonging to the same group as Pd and capable of splitting molecular hydrogen has been selected. Herein, a simple two-step synthesis procedure involving nontoxic precursors was used to synthesize bulk nickel phosphides with different stoichiometries (Ni2P, Ni5P4, and Ni12P5) by controlling the P:Ni ratios. To uncover structural and surface features, this catalyst family is characterized with an array of methods including X-ray diffraction (XRD), 31P magic-angle nuclear magnetic resonance (MAS-NMR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Bulk-sensitive techniques prove the successful preparation of pure phases while XPS analysis unravels the facile passivation occurring at the NixPy surface that persists even after reductive treatment. To assess the characteristic surface fingerprints of these materials, Ar sputtering was carried out at different penetration depths, reveling the presence of Ni+ and P-species. Continuous-flow three-phase hydrogenations of short-chain acetylenic compounds display that the oxidized layer covering the surface is reduced under reaction conditions, as evidenced by the induction period before reaching the steady state performance. To assess the impact of the phosphidation treatment on catalytic performance, the catalysts were benchmarked against a commercial Ni/SiO2-Al2O3 sample. While Ni/SiO2-Al2O3 presents very low selectivity to the alkene (the selectivity is about 10% at full conversion) attributed to the well-known tendency of naked nickel nanoparticles to form hydrides, the performance of nickel phosphides is highly selective and independent of P:Ni ratio. In line with previous findings on PdxS, kinetic tests indicate the occurrence of a dual-site mechanism where the alkyne and hydrogen do not compete for the same site.
This work is the subject of a publication of which I am a co-author, as cited below.
D. Albani; K. Karajovic; B. Tata; Q. Li; S. Mitchell; N. López; J. Pérez-Ramírez. Ensemble Design in Nickel Phosphide Catalysts for Alkyne Semi-Hydrogenation. ChemCatChem 2019. doi.org/10.1002/cctc.201801430
ContributorsTata, Bharath (Author) / Deng, Shuguang (Thesis director) / Muhich, Christopher (Committee member) / Chemical Engineering Program (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This creative project explores how macro-ecological photography can serve as a community engagement tool for the field of biomimicry, meant to provoke interest in the subject. My photos, and the organisms pictured in them, were hand selected for this project to form one cohesive, aesthetic set. The appeal of the colorful pictures captured the attention of audience members so they felt more inclined to learn about the informational content accompanying the art. Each picture is coupled with a scientific explanation as to how the pictured organism relates to the field of biomimicry, including concrete examples of its application. To maximize exposure of the project, I published my photos through a website and an e-book, and also presented them as a live photography exhibit on campus at Arizona State University.
ContributorsGerber, Haley Dawn (Author) / Jenik, Adriene (Thesis director) / Walters, Molina (Committee member) / Division of Teacher Preparation (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Circles of Sustainability is a self-evaluation tool designed to build educator capacity in K-12 schools seeking sustainability solutions. Based on the Sustainable Schools Challenge Handbook from Memphis, Tennessee, Circles of Sustainability considers environmental impact and efficiency, a healthy and safe school environment, sustainability and environmental education, and engagement and empowerment as four key pillars of whole-school sustainability. Each pillar is composed of elements and rubric items, which are reviewed, totaled, and colored in on the front page of the tool to help educators visualize and evaluate the current state of sustainability at their school. Since its first iteration completed in May 2017, the tool has been used by 300 educators throughout the United States during ASU's Sustainability Teachers' Academy (STA) workshops. Circles of Sustainability is completed as part of an activity called "Evaluating Your Community," where educators complete the tool and then brainstorm sustainability projects and solutions for their school and community. This paper is a review and discussion of the research, informal feedback and formal feedback used to create the second iteration of the tool. A second iteration of the tool was created to make the tool more user-friendly and ensure each pillar, element, and rubric item are based in research. The informal feedback was conducted during STA workshops in Tempe, Arizona; Abingdon, Virginia; Princeton, New Jersey; Chicago, Illinois; Los Angeles, California; Tucson, Arizona; and Charlotte, North Carolina. The formal feedback was conducted using a survey distributed to teachers who participated in the Tucson and Charlotte workshops. Overall, educators have responded positively to the tool, and the second iteration will continue to be used in future STA workshops throughout the United States.
ContributorsColbert, Julia (Author) / Schoon, Michael (Thesis director) / Merritt, Eileen (Committee member) / School of Sustainability (Contributor) / Division of Teacher Preparation (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
With the overall health of the environment rapidly declining \u2014 mostly due to human behaviors, solving the problem of nature deficit disorder and getting more children interested and aware of nature could be paramount to improving the environmental health of our planet. In this study, the relationship between children's learning and emotion is explored. Pre- and post-tests were given to children attending a week-long summer freshwater ecology camp; their knowledge of and emotional connection to different ecological concepts were measured. Two separate ecosystems were tested \u2014 a freshwater ecosystem that was taught over the course of the week, and a marine ecosystem for comparison. Increases in knowledge and emotion were seen in every freshwater ecosystem concept. Additionally, the knowledge and emotion scores were correlated, suggesting a positive relationship between them. The marine ecosystem did not show improvements in concrete knowledge, but showed increases in abstract learning, indicating that the abstract concepts learned about the freshwater ecosystem were able to transfer to the marine. Overall results show the ability of a hands-on learning experience to foster an emotional connection between a child and the subject matter. However, long-term studies are needed to track the relationship between children and their knowledge of and emotional connection to the subject matter.
ContributorsMossler, Max Vaughn (Author) / Pearson, David (Thesis director) / Smith, Andrew (Committee member) / Berkowitz, Alan (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
The existing educational system is failing to provide adequate environmental education to future generations so that they will have the knowledge, skills, and capability to address the environmental concerns that society is facing. The system must encompass environmental education through adoption of an eco-pedagogical system that either contributes to traditional education or is utilized on its own. The eco-pedagogical system produces education from a social and ecological point of view. As a result of the approach, students would develop and form a connection to nature as well as environmental hope. Each of these components will contribute to the student’s motivation, pathway thinking, agency thinking, and social trust. Leading to the development of the student's aptitude and capability to establish a goal and a plan to achieve it, as well as the identification of potential barriers and strategies for overcoming them. Ultimately, environmental education will equip future generations with the knowledge and skills necessary to create a social system that is capable of sustaining life while also caring for the environment and addressing environmental concerns produced by anthropocentric consequences.
Keywords: Environmental education, eco-pedagogy, connection to nature, environmental hope
Website Link: https://kvidean43.wixsite.com/environmentaled
ContributorsVidean, Kira (Author) / Bowman, Diana (Thesis director) / Serafini, Frank (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Social Transformation (Contributor)
Created2022-05
Description
The existing educational system is failing to provide adequate environmental education to future generations so that they will have the knowledge, skills, and capability to address the environmental concerns that society is facing. The system must encompass environmental education through adoption of an eco-pedagogical system that either contributes to traditional education or is utilized on its own. The eco-pedagogical system produces education from a social and ecological point of view. As a result of the approach, students would develop and form a connection to nature as well as environmental hope. Each of these components will contribute to the student’s motivation, pathway thinking, agency thinking, and social trust. Leading to the development of the student's aptitude and capability to establish a goal and a plan to achieve it, as well as the identification of potential barriers and strategies for overcoming them. Ultimately, environmental education will equip future generations with the knowledge and skills necessary to create a social system that is capable of sustaining life while also caring for the environment and addressing environmental concerns produced by anthropocentric consequences. Keywords: Environmental education, eco-pedagogy, connection to nature, environmental hope Website Link: https://kvidean43.wixsite.com/environmentaled
ContributorsVidean, Kira (Author) / Bowman, Diana (Thesis director) / Serafini, Frank (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2022-05
Description
The existing educational system is failing to provide adequate environmental education to future generations so that they will have the knowledge, skills, and capability to address the environmental concerns that society is facing. The system must encompass environmental education through adoption of an eco-pedagogical system that either contributes to traditional education or is utilized on its own. The eco-pedagogical system produces education from a social and ecological point of view. As a result of the approach, students would develop and form a connection to nature as well as environmental hope. Each of these components will contribute to the student’s motivation, pathway thinking, agency thinking, and social trust. Leading to the development of the student's aptitude and capability to establish a goal and a plan to achieve it, as well as the identification of potential barriers and strategies for overcoming them. Ultimately, environmental education will equip future generations with the knowledge and skills necessary to create a social system that is capable of sustaining life while also caring for the environment and addressing environmental concerns produced by anthropocentric consequences. Keywords: Environmental education, eco-pedagogy, connection to nature, environmental hope Website Link: https://kvidean43.wixsite.com/environmentaled
ContributorsVidean, Kira (Author) / Bowman, Diana (Thesis director) / Serafini, Frank (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2022-05