Iron polypyridyl complexes for electrocatalytic proton reduction

Zachary Schiffman, ANYL 1st year student

"In recent decades the rate of human consumption has accelerated dangerously. This is especially true of energy, the usage of which is unsustainable for long-term continuation at the current rate. We should then turn to renewable energy using materials that can be used infinitely, as opposed to fossil fuels which are notably finite and are contributing to the continuously rising levels of greenhouse gas pollution.

Solar energy would be a source of clean energy. An idea for a method of harnessing and storing solar energy is inspired by Earth’s plant life. In the process of photosynthesis, plants take in sunlight and store the solar energy in the form of chemical bonds. Just as plants reduce carbon dioxide to produce sugars as fuel, we look to use the energy of the sun to reduce protons from water into hydrogen gas, which burns cleanly with no CO2 emission. Metal-based complexes have been developed which can act as catalysts for this hydrogen evolution reaction (HER). Many of these complexes are synthesized in lengthy, low-yielding processes. In terms of developing practical technology that can be used on a large scale, it is best to synthesize these complexes in a straightforward, easy synthesis using inexpensive, commercially available materials.

We produced a tridentate bismethylpyridyl amine bound to an iron (III) center. This complex is synthesized from commercially available materials in high yield, and was shown to be an active electrocatalyst for proton reduction. Cyclic voltammetric techniques were used to verify and benchmark the complex’s activity and efficiency as an electrocatalyst. It was also shown to be active as a pre-catalyst in a three-component system for photocatalytic hydrogen generation. To this end, we seek to simplify our catalyst precursors to produce a readily synthesized complex that can be obtained at low cost and in high yields. This may take us one step closer to developing a wide-spread, accessible system for artificial photosynthesis."

and

Synthesis of Phosphate Diesters for use as Ligands on Bismuth Catalysts

Bri Dobson, ANYL 1st year

"New catalysts can simplify synthetic schemes or open up new possibilities in synthetic chemistry. In particular, bismuth phosphates have shown promise as an expanding family of green catalysts. Some bismuth compounds have Lewis acid catalyst properties but need to be made more effective in order to be used industrially. Phosphate diesters with varying ester groups may be able to tune the activity of these catalysts to fit specific reactions. With the final goal of creating a tunable bismuth phosphate diester catalyst, this project attempted to find a simple, but effective method for synthesizing a variety of phosphate diesters, which could then be used as ligands on homogenous bismuth phosphate diester Lewis acid catalysts for a variety of different synthetic uses. Two schemes for phosphate diester synthesis were attempted. One of the two was successful in the synthesis of pentamethylene phosphate. Further testing with different reagents is needed to establish the applicability of this scheme to the synthesis of other phosphate diesters, but the preliminary results are promising."

Please note: seminar starts at 12:40 PM. Contact anne.handschy@colorado.edu for Zoom link.

Presenter: Ryan Cassotto
Topic: TBA - Glaciology

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About the series: The CIRES/NOAA Science-at-Home Virtual Speaker Series runs at 1pm Tuesdays and is designed to show young students at home the work being done at CIRES and NOAA, and offer recommendations to activities that can be done at home to reinforce learning

ESOC virtual coffee hour occurs weekly from 9-10am on Wednesdays. We will be meeting remotely on Zoom. Please email Claire Waugh (waughc@colorado.edu) for information.

ESOC researchers, post-docs and graduate students gather for conversation and to discuss research. Occasional guest speakers are invited to give short presentations on topics of interest.

Please join CIRES Director Waleed Abdalati for another CIRES Town Hall on Monday, November 9, 2020.

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https://cuboulder.zoom.us/j/94500406761

Presenter: Twila Moon
Topic: Ice Dynamics

Register for this FREE event.

About the series: The CIRES/NOAA Science-at-Home Virtual Speaker Series runs at 1pm Tuesdays and is designed to show young students at home the work being done at CIRES and NOAA, and offer recommendations to activities that can be done at home to reinforce learning

ESOC virtual coffee hour occurs weekly from 9-10am on Wednesdays. We will be meeting remotely on Zoom. Please email Claire Waugh (waughc@colorado.edu) for information.

ESOC researchers, post-docs and graduate students gather for conversation and to discuss research. Occasional guest speakers are invited to give short presentations on topics of interest.

Role of the Metal Support Interface in H2 Activation on Supported Gold Nanoparticles

Alexander Bradley, ANYL 1st year student

"Global Hydrogen production exceeds 50 million tons per year, largely for the production of ammonia. Given its importance, a fundamental understanding of hydrogen activation is vital when designing new catalysts. Hydrogen activation on gold catalysts is poorly understood and understudied, and the weak adsorption effects allow only a few types of experimental measurements. We have developed a kinetic model for analyzing hydrogen binding parameters on gold, and a method for extracting a proposed mechanism.

Hydrogen is thought to activate homolytically on late transition metals, but recent evidence suggests that it activates heterolytically at the metal-support interface of supported gold catalysts. The thermodynamic properties of this reaction were calculated by Van’t Hoff analysis. Enthalpy and entropy terms were found to be much lower than popular supported metals (Ni, Rh, etc). Kinetic Isotope Effect (KIE) experiments were carried out to determine the nature of the hydrogen activation, and whether the mechanism includes a proton coupled electron transfer (PCET) step."

and

Theoretical Examination of Isoprene’s Behavior at the Air-Water Interface

Kyle McMillan, ANYL 1st year student

"Isoprene is the most widely emitted biogenic hydrocarbon in the atmosphere (approximately 500 Tg emitted annually), making it a significant player in atmospheric chemistry. So far, most research concerning isoprene’s role in the atmosphere has examined its gas-phase chemistry with little consideration given to its potentially significant chemistry within clouds. The purpose of this study was to elucidate isoprene’s behavior at the air-water interface of a water droplet. To do this, high level molecular dynamics (MD) calculations were utilized to simulate isoprene’s interaction with a droplet of 10-nm diameter. The data generated by these calculations were then used to describe both isoprene’s conformational dynamics and chemical group orientations at the air-water interface, looking closely at the torsion angles of both its s-trans and s-gauche conformers as well as the distances between each of its atoms and the water molecules comprising the water droplet. Though the results of this study were not wholly conclusive, due primarily to incomplete datasets generated by the MD calculations, there were some indications of potentially favorable interactions of isoprene with the air-water interface, especially for its s-gauche conformer. Should the air-water interface selectively alter the chemical properties of either of isoprene’s two major conformers (for example, by augmenting the reactivity of either toward a major atmospheric oxidant such as OH) this would have clear implications for isoprene’s chemistry in the troposphere, which has been shown to vary significantly with conformational state."

Join James Rattling Leaf Sr. for a discussion of best practices to establish relationships and collaborations with Indigenous communities.

James Rattling Leaf Sr. will outline recommendations for working with Indigenous communities based on the knowledge that long term relationship building with these communities is the foundation upon which educational programs, research collaborations, and other initiatives must be co-created.

This presentation seeks to define best practices in approach and process for establishing and maintaining effective collaborations with Indigenous communities that respect sovereignty and self-determination and which have application across many types of efforts.

These practices will have a lasting impact on Equity, Diversity and Inclusion at universities, professional societies, educational organizations, and agencies, on the STEM workforce broadly, and for Indigenous youth and communities toward realization of their dreams and aspirations.

For more info, visit the CIRES Diversity and Inclusion website & register online on Eventbrite.

Snow-Glacier dynamics and its interaction with the hydrology in Hindukush-Karakoram and Himalayas region of Pakistan by Huma Hayat

The agriculture-based economy of Pakistan largely depends on the water supply from the Upper Indus Basin (UIB) originating in the Hindukush-Karakoram-Himalaya (HKH) range. The UIB supplies more than 70% of the flow to the downstream agricultural areas during summer. It is mainly fed by snow and glacial melt water from Hindukush-Karakoram and Himalaya (HKH) mountain ranges.  For efficient management of downstream water resources, studying snow and glacier cover dynamics and their relation with the hydrology of the UIB is a prerequisite. The network of meteorological stations within the UIB is very sparse and mainly limited to Pakistan’s political boundary, therefore remote sensing data is the most reliable alternative. This study estimates snow and glacier dynamics and their interaction with the hydro-climatological processes in Chitral, Hunza, and Astore sub-basins of UIB. This will contribute to a better understanding of the complex hydroclimatic regime of the high-altitude snow- and glacier-fed Indus river catchment.

Huma Hayat is a Ph.D. student in the Department of Environmental Sciences at COMSATS University Islamabad, Pakistan. Her research is on the snow and glacier dynamics in the Hindukush, Karakoram, and western Himalaya region of Pakistan using remote sensing.

TO JOIN BY ZOOM:

• From a computer: https://cuboulder.zoom.us/j/5409618610
• Or iPhone one-tap : US: +16465588656,,5409618610#
• Or Telephone:  US: +1 646 558 8656
• Meeting ID: 540 961 8610
• International numbers available: https://zoom.us/u/MNl8z 

Save the date for the CIRES’ Innovative Research Program (IRP) Virtual Poster Session and Q&A on Thursday, November 19. The event will feature the research results of last year's IRP winners, listed below. This year's format will include introductions by Waleed Abdalati, CIRES Director, and Christine Wiedinmyer, CIRES Associate Director for Science, as well as short presentations from each IRP Winner followed by a Q&A virtual session with the presenters.

The IRP is an internal CIRES competition designed to stimulate a creative research environment within CIRES and to encourage synergy between disciplines and research colleagues. The program encourages novel, unconventional or fundamental research that might otherwise be difficult to fund. CIRES-wide competitions are conducted each year to foster an innovative research environment where risk taking is allowed and even encouraged.

2019 IRP Recipients:

Accelerometer-Based Turbulence Profile Sensors for Low-Cost Determination of Boundary Layer Height from Small Aircraft

Investigators: Kathryn McKain with Philip Handley and Isaac Vimont

Zoom Link

Video In-Situ Snowfall Sensor (VISSS)

Investigators: Max Maahn with Matthew Shupe and Taneil Uttal

Zoom Link

Assessing the Potential of Biometric Sensors to Measure Engagement and Learning in the Classroom

Investigators: Jen Kay and Anne Gold with Ariel Morrison

Zoom Link

First satellite mapping of nitrous acid (HONO) in wildfire plumes

Dr. Nicolas Theys,
Royal Belgian Institute for Space Aeronomy (BIRA-IASB)

"Nitrous acid (HONO) is a short-lived reactive gas and plays a key role in the atmosphere through its influence on the OH budget, and contributes to secondary aerosols and ozone formation. Laboratory experiments and aircraft field campaigns have revealed that biomass burning is a source of HONO. However, the global importance of pyrogenic HONO is poorly constrained. Here we present the first global measurements of HONO using the TROPOspheric Monitoring Instrument (TROPOMI) onboard Sentinel-5 Precursor. Using Differential Optical Absorption Spectroscopy (DOAS) applied in the UV, we analyzed one year of TROPOMI data and found that HONO is unambiguously detected in wildfire plumes from main biomass burning regions, consistent with volume mixing ratios of several ppbvs of HONO.

During July-September 2018, the University of Colorado participated to a field campaign (Biomass Burning Fluxes of Trace Gases and Aerosols (BB-Flux)), performed research flights near fire plumes in the US and successfully detected HONO for several of them using the CU-DOAS aircraft instrument. For some cases, flights were planned around the TROPOMI overpass. We exploit this unique opportunity to validate our satellite HONO retrievals. We discuss the comparison results and reasons for discrepancies. In particular, viewing observations are very different and can lead to air mass sampling differences in the presence of elevated aerosols. To overcome this problem, we compared the ratio HONO/NO2 (RHN), which is also a proxy for HONO production. We found that satellite and aircraft RHNs are in excellent agreement, within their mutual error estimates. From the global RHNs, we demonstrate that previous assessments underestimate pyrogenic HONO emissions by a factor of 2–4 across all ecosystem types.

Finally, we performed model simulations to assess the impact of HONO on atmospheric oxidants, such as OH and tropospheric ozone. We estimate that HONO emissions are responsible for two-thirds of the OH production in fresh wildfire plumes worldwide and act to accelerate oxidative plume chemistry and ozone production. Our findings suggest that pyrogenic HONO emissions have a substantial impact on atmospheric composition, which enhances regional ozone levels by up to 7 ppbv."

N. Theys, R. Volkamer, J.-F. Müller, K. Zarzana, N. Kille, L. Clarisse, I. De Smedt, C. Lerot, H. Finkenzeller, F. Hendrick, T. Koenig, C.F. Lee, C. Knote, H. Yu, M. Van Roozendae.

Please note that the seminar begins at 12:40. For the Zoom link email anne.handschy@colorado.edu

Prototype Readout System Software for The STAR Interlock Safety System at Brookhaven National Laboratory

Joseph D'alesio, ANYL First Year

"RHIC, located at BNL, collides nuclei at relativistic speeds to artificially recreate the initial conditions of the universe. The STAR Collaboration studies these collisions using a detector, the Solenoidal Tracker At RHIC. The Interlock Safety System is responsible for monitoring and displaying parameters in the STAR control room. These parameters include the temperature and pressure of the TPC gas mixture, the Oxygen Deficiency Hazard status, the Uninterruptable Power Supply status and the water cooling system status. If these parameters fall outside an accepted range, alarms will sound to notify the control room. The readout system and software allow for the shift operator to adjust detector variables while the experiment is running and thus prevent circumstances in which fires and explosions are likely. This project focuses on upgrades to the Interlock monitoring system. The current Interlock Readout monitor uses a VME to communicate with various STAR systems while the upgraded monitor uses a Programmable Logic Controller interfaced to a PC. Device support for the upgraded monitor has been written and compiled using a prototype input/output controller program to communicate to the new readout PLC. Functionally, the existing and upgraded system will have the same capabilities. However, the new readout system will be easier to maintain and more easily updated to include, for example, additional safety signal outputs. In turn, this will result in a critical readout system prepared for future operations."

For access, please contact Anne.Handschy@colorado.edu. Note that the seminar begins at 12:40, and this is a half seminar, ending around 1:10 PM.