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Heterogeneous Catalysis for Organic Reactions

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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

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

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2019-05

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An Exploration of Climate Change's Impact on The Coffee Industry

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Coffee is one of the most widely consumed beverages in the world, with a staggering 1.4 billion cups of coffee poured a day (Coffee Consumption around the World). One-point six percent of total US GDP is made up by coffee

Coffee is one of the most widely consumed beverages in the world, with a staggering 1.4 billion cups of coffee poured a day (Coffee Consumption around the World). One-point six percent of total US GDP is made up by coffee operations and fuels 1.6 million jobs in the United States (The Global Coffee Industry). However, with an increasingly complex political and economic world, along with the threat of climate change, the world’s coffee supply is at risk of total collapse. There are two primary varieties of coffee consumed in the world, Arabica and Robusta coffee. Most coffee producing countries run along the equator and are generally classified as developing economies. The global south is relied upon for coffee production. “Across Mexico and Central America, over 4 million people depend directly on coffee production for their livelihoods” (An Integrated Framework). Coffee production helps boost these economies and support families financially, with many workers having to support dependent individuals.

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2020-05

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Nemo's Future: A Systematic Quantitative Literature Review on the Effects of Ocean Acidification on Fish Behavior

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Anthropogenic climate change caused by increasing carbon emissions poses a threat to nearly every living organism. One consequence of these emissions is ocean acidification (OA). While OA has been shown to directly inhibit growth in calcifying animals, it might also

Anthropogenic climate change caused by increasing carbon emissions poses a threat to nearly every living organism. One consequence of these emissions is ocean acidification (OA). While OA has been shown to directly inhibit growth in calcifying animals, it might also have negative effects on other marine life. I conducted a systematic quantitative literature review on the effects of OA on fish behavior. The review consisted of 29 peer-reviewed, published journal articles. Most articles report some degree of negative impact of OA. Impacts include sensory impairment, erratic swimming patterns and attraction to predators. Many studies report insignificant impacts, thus continued research is needed to understand the consequences of human behavior and assist in mitigating our impact.

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2020-05

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Farms of the Future: Food Security in a Changing World

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The purpose of this thesis is to imagine and predict the ways in which humans will utilize technology to feed the world population in the 21st century, in spite of significant challenges we have not faced before. This project will

The purpose of this thesis is to imagine and predict the ways in which humans will utilize technology to feed the world population in the 21st century, in spite of significant challenges we have not faced before. This project will first thoroughly identify and explain the most pressing challenges the future will bring in climate change and population growth; both projected to worsen as time goes on. To guide the prediction of how technology will impact the 21st century, a theoretical framework will be established, based upon the green revolution of the 20th century. The theoretical framework will summarize this important historical event, and analyze current thought concerning the socio-economic impacts of the agricultural technologies introduced during this time. Special attention will be paid to the unequal disbursement of benefits of this green revolution, and particularly how it affected small rural farmers. Analysis of the technologies introduced during the green revolution will be used to predict how 21st century technologies will further shape the agricultural sector. Then, the world’s current food crisis will be compared to the crisis that preceded the green revolution. A “second green revolution” is predicted, and the agricultural/economic impact of these advances is theorized based upon analysis of farming advances in the 20th century.

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2019-05

How to Create Buzz in Environmental Reporting: The Best Practices for Effective and Captivating Storytelling

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Journalism is one of the most far-reaching mediums to inform the public about environmental and sustainability issues. Mass communication has brought this discussion to an unprecedented level of exposure that continues to escalate, and the quality of storytelling must continue

Journalism is one of the most far-reaching mediums to inform the public about environmental and sustainability issues. Mass communication has brought this discussion to an unprecedented level of exposure that continues to escalate, and the quality of storytelling must continue to spark discussion about sustainability and environmental problems. The quality of environmental journalism, the “researching, verifying, writing, producing and broadcasting of news about the environment” to and for the public sphere, has been a subject of much debate (Pezzullo & Cox, 2012). This beat, relatively new, is an emerging one that serves the public by explaining the importance of protecting and preserving the environment. However, sometimes journalists’ work falls on deaf ears. In order for environmental journalists to be effective storytellers with robust, reliable work that resonates with audiences, they must continue to improve the effectiveness and captivating qualities of their work.
This project will explore how the American public perceives environmental reporting, constraints on its production, an assessment of the industry’s success and growth, and advice from current journalists. I will conclude with a list of the best practices for captivating and effective storytelling. Finally, I will close with a reflection based upon my creative project, a multimedia piece on how citrus crops in Arizona are affected by honey bees. I aim to provide student journalists with an informal guide to the key skills that will help them excel not only in reporting on a certain sustainability topic, but also on the environment as a whole.

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2019-05

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Reducing Livestock-based Emissions in Argentina: Analyzing Climate Change Mitigation Strategies through Policy and Governance in the Agricultural Sector

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Intensive global animal agricultural practices have proved to be a cause for concern, resulting, in part, from consumer preferences and an increasing global demand for protein, especially meat. Countries like Argentina, contribute to Greenhouse Gas emissions substantially through their livestock

Intensive global animal agricultural practices have proved to be a cause for concern, resulting, in part, from consumer preferences and an increasing global demand for protein, especially meat. Countries like Argentina, contribute to Greenhouse Gas emissions substantially through their livestock sector. Improved resource management can help to promote sustainable agriculture by reducing the amount of water and energy used to produce livestock, and improve livestock practices in order to reduce GHG emissions. The integration of resource management between food, energy, and water systems can help to decrease livestock-based emissions, through efficiency improvements targeted towards animal agricultural practices. This paper can act as a reference for other researchers studying the FEW nexus, to increase their understanding of how to improve coordination across water, energy, and agricultural sectors by using Argentina’s livestock sector as an example. Furthermore, policy and decision makers in Argentina can use information about FEW systems to make informed decisions about the allocation and prioritization of integrated management between food, energy, and water sectors, to help them implement integrated mitigation strategies within their livestock sector to help reduce GHG emissions.

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2020-12

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A Sunrise on a New Future: How the Sunrise Movement is Reshaping Environmental Activism

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Environmental activism has played a major role in American politics since the late 1800s, with major victories including the National Park Service Organic Act of 1916 that established the National Park Service to help protect parks and monuments, the Clean

Environmental activism has played a major role in American politics since the late 1800s, with major victories including the National Park Service Organic Act of 1916 that established the National Park Service to help protect parks and monuments, the Clean Air and Clean Water Acts of the 1960s and 1970s, and the phase-out of ozone depleting chemicals in the 1990s. Yet mainstream activism has stagnated in recent years, facing a variety of problems such as continuing to perpetuate a corporate system in which frontline and minority communities are left behind and only focusing on traditional methods like lobbying and indirect activism that fail to generate mass public support. In contrast, the Sunrise Movement is a new youth-oriented environmental and social organization that has become prevalent in the last five years for their aim to combat both climate change and socioeconomic inequalities through the Green New Deal. With the growing need for climate action that is fair and equitable, this project intended to contextualize the Sunrise Movement within past and current environmental movements as well as the current environmental and political climate in order to then investigate how Sunrise operates and their level of effectiveness in promoting the Green New Deal. I performed a literature review of both past and present news articles as well as journal articles in addition to interviewing experts in the theory and practice of activism to characterize the three waves of environmentalism and lessons learned, the current political sphere and what mainstream activism is working toward, and Sunrise itself. While mainstream and localized radical activism had victories and a certain degree of effectiveness, their lack of inclusivity has failed to encourage the mass mobilization needed for long-term climate legislation. The Sunrise Movement distinguishes itself through disruptive activism and direct engagement: disruptive by challenging the status quo of profit over people, the two party system where both groups are moving toward the right, and the whiteness and liberal locations of the mainstream environmental movement; direct by working with partners across the environmental, social, and labor sphere and working with actionable, hands-on items that encourage participation. Though they have major limitations like ensuring that they are as inclusive as they recognize an environmental movement must be and the risk of being seen as a partisan organization, Sunrise shows that the attitude of the public is moving in favor of the climate and social equity.

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2020-12

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Youth are the Present: An Analysis on the Different Experiences of Youth Climate Activists and Organizers in Arizona

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The goal of this paper is to serve as a case-study of the youth climate movement at the local level, focusing on how young activists and organizers in Arizona perceive their pathways, motivators, and barriers in the climate movement. In

The goal of this paper is to serve as a case-study of the youth climate movement at the local level, focusing on how young activists and organizers in Arizona perceive their pathways, motivators, and barriers in the climate movement. In order to answer my research question of ‘What are the different experiences of Arizona youth activists’ involvement in climate action?’, I conducted a case-study of 15 interviews with participants between the ages of 18-25 that varied in racial and gender identity, as well as the duration of their involvement. While this paper does not present a comprehensive view of all experiences of youth climate activists and organizers in Arizona, these interviews highlight the upbringing, background, and the degree of involvement of young climate organizers and activists, ultimately revealing their similar yet unique experiences in the climate movement. Even though further research, discussion, and opportunities are needed to better understand the youth climate movement as well as other emerging social movements, these participants represent the heart of the movement here in Arizona. This case-study sheds light on lived-experiences and urges readers to consider young climate activists and organizers’ varying perspectives on how to support, amplify, and implement their requests for a livable, intersectional, diverse, and inclusive future.

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2020-12

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Addressing International Implications of Adverse Climate Impacts in the Arctic: A Case Study Analysis on the Challenge of Hazardous Waste Reintroduction due to Ice Melt at Camp Century, Greenland

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Buried under ice and snow in Greenland, the abandoned Camp Century holds the remnants of a Danish-American Cold War-era operation left to achieve final disposal beneath a tomb of ice. Nearly 50 years later, climate projections hypothesize that snowmelt will

Buried under ice and snow in Greenland, the abandoned Camp Century holds the remnants of a Danish-American Cold War-era operation left to achieve final disposal beneath a tomb of ice. Nearly 50 years later, climate projections hypothesize that snowmelt will exceed snowfall in 2090—releasing the trapped hazardous wastes at Camp Century. This thesis examines the mechanisms through which the international community is able to remediate climate change impacts on Camp Century wastes. The wastes are characterized and examined as either a problem of transboundary pollution, as an issue of military accountability, or as an issue of climate change policy. As revealed, the wastes are unable to be classified as transboundary pollutants. Though classified as a point-source transboundary risk, they are neither a traded or public risk. Furthermore, no international or domestic transboundary pollution agreements incorporate provisions encompassing the specific attributes of Camp Century’s waste. Camp Century is also not an issue of military accountability as U.S. base cleanup laws and environmental regulations do not apply abroad and as the original bilateral agreement governing the site is insufficient in addressing potential ice melt. Finally, as examined through institutions such as the UNFCCC and the Paris Agreement, Camp Century is, again, unable to be incorporated in current frameworks such as adaptation as adaption efforts are concentrated on developing nations. This thesis reveals the inability of current frameworks, institutions, and agreements to effectively remediate Camp Century wastes which is a case utilized as a microcosm through which to examine international capacity in addressing climate-change induced impacts.

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2016-12