Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Water-cleanup catalysts tackle biomass upgrading: Rice University researchers register 4th 'volcano plot' for palladium-gold catalysts

Rice University scientists (from left) Michael Wong, Zhun Zhao and James Clomburg discovered a palladium and gold nanocatalyst that is faster -- about 10 times faster -- at converting glycerol into high-value products than catalysts of either metal alone.  
CREDIT: Jeff Fitlow/Rice University
Rice University scientists (from left) Michael Wong, Zhun Zhao and James Clomburg discovered a palladium and gold nanocatalyst that is faster -- about 10 times faster -- at converting glycerol into high-value products than catalysts of either metal alone.

CREDIT: Jeff Fitlow/Rice University

Abstract:
Rice University chemical engineer Michael Wong has spent a decade amassing evidence that palladium-gold nanoparticles are excellent catalysts for cleaning polluted water, but even he was surprised at how well the particles converted biodiesel waste into valuable chemicals.

Water-cleanup catalysts tackle biomass upgrading: Rice University researchers register 4th 'volcano plot' for palladium-gold catalysts

Houston, TX | Posted on June 26th, 2014

Through dozens of studies, Wong's team focused on using the tiny metallic specks to break down carcinogenic and toxic compounds. But his latest study, which is available online and due for publication in an upcoming issue of the Royal Society of Chemistry's journal Chemical Science, examined whether palladium-gold nanocatalysts could convert glycerol, a waste byproduct of biodiesel production, into high-value chemicals.

In scientific parlance, the data from the study produced a "volcano plot," a graph with a sharp spike that depicts a "Goldilocks effect," a "just right" balance of palladium and gold that is faster -- about 10 times faster -- at converting glycerol than catalysts of either metal alone.

"We've now seen this volcano plot at least four times now, first with TCE, then with the dry cleaning contaminant 'perc,' and more recently with chloroform and nitrites," Wong said. "The remarkable thing is that the reaction, in each case, is very different."

In previous studies, the nanocatalysts were used in reduction reactions, chemical processes marked by the addition of hydrogen. In the latest tests on glycerol conversion, the nanocatalysts spurred an oxidation reaction, which involves adding oxygen.

"Oxidation and reduction aren't just dissimilar; they're often thought of as being in opposite directions," Wong said.

In chemistry, the role of the catalyst is much like that of a matchmaker; catalysts cause other compounds to react with one another, often by bringing them into close proximity, but the catalysts themselves don't take part in the reaction. Catalysts often speed up reactions that would otherwise happen too slowly, and drugmakers and chemical companies use catalysts to improve the efficiency of their chemical processing. The global market for industrial catalysts is projected to top $19 billion by 2016.

Palladium and gold -- and mixtures of the two -- have long been recognized as extremely effective catalysts. Among catalysts, gold is now valued because it doesn't tarnish or oxidize, a process that can shorten a catalyst's lifespan. Palladium is typically prized because it is especially good at binding and inducing molecules to reduce or oxidize. Wong and colleagues have demonstrated a way to bring these two metals together with better control. They build their catalysts on gold spheres that are about four nanometers in diameter. The spheres are partially covered with palladium, so that the particles' surface contains some gold and some palladium.

Wong and colleagues have shown that covering 60-80 percent of the gold's surface area with palladium typically produces the ideal catalyst -- though the exact percentage varies for different reactions.

"Our synthesis knob, the thing we use to dial in the efficiency, is the coverage area, and the precision of that knob is really what sets us apart from other people who are studying bimetallic catalysis," Wong said. "That precision is what produces these beautiful volcano plots, but it also helps in another way because it allows us to develop a rigorous explanation for the effects that we're measuring."

In the latest study, Wong, Rice graduate student and lead author Zhun Zhao and colleagues from Rice, Argonne National Laboratory and the University of Groningen in Holland used high-powered X-ray spectroscopy and other techniques to show that the "Goldilocks" coverage area for glycerol catalysis was about 60 percent.

"Palladium by itself oxidizes, which is not good because it slows down the catalysis," Zhao said. "We found that the gold in our catalysts helps stabilize the palladium and prevents it from degrading. The catalysts in our tests had extremely high durability. Our best catalyst produced a glycerol product with higher purity and in less time than anything else we found in the literature."

Wong said the research opens up an exciting new area of exploration for his lab.

"Now that we understand how these work with glycerol, we can study reactions of other biomass molecules like glucose, a building block of plants," Wong said.

Additional co-authors include Rice's Lori Pretzer, Pongsak Limpornpipat, James Clomburg and Ramon Gonzalez, Groningen's Joni Arentz and Argonne's Neil Schweitzer, Tianpin Wu and Jeffrey Miller. The research was supported by the National Science Foundation, the Welch Foundation, the Sigma Xi Grants-in-Aid of Research program, Rice University and the Department of Energy.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is 6.3-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance.

Follow Rice News and Media Relations on Twitter @RiceUNews.

For more information, please click here

Contacts:
Jade Boyd
713-348-6778

Copyright © Rice University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

A copy of the Chemical Science paper is available at:

Related News Press

News and information

Graphene and Amaranthus Superparamagnets: Breakthrough nanoparticles discovery of Indian researcher September 23rd, 2014

New NIH/DOE Grant for Life Science Studies at NSLS-II: Funding will support operation of three powerful experimental stations designed to reveal detailed structures of proteins, viruses, and more September 23rd, 2014

BSA Distinguished Lecture Tuesday, 10/14: 'LCLS: A Stunning New View Through X-ray Laser Eyes' September 23rd, 2014

Brookhaven Lab's National Synchrotron Light Source II Approved to Start Routine Operations: Milestone marks transition to exciting new chapter September 23rd, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 2014

Chemistry

Brookhaven Lab's National Synchrotron Light Source II Approved to Start Routine Operations: Milestone marks transition to exciting new chapter September 23rd, 2014

Production of Organometallic Frameworks in Least Possible Time September 23rd, 2014

Govt.-Legislation/Regulation/Funding/Policy

Brookhaven Lab's National Synchrotron Light Source II Approved to Start Routine Operations: Milestone marks transition to exciting new chapter September 23rd, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 2014

Nanotubes help healing hearts keep the beat: Rice University, Texas Children’s Hospital patch for defects enhances electrical connections between cells September 23rd, 2014

Immune system is key ally in cyberwar against cancer: Rice University study yields new two-step strategy for weakening cancer September 23rd, 2014

Discoveries

Graphene and Amaranthus Superparamagnets: Breakthrough nanoparticles discovery of Indian researcher September 23rd, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 2014

Future flexible electronics based on carbon nanotubes: Study in Applied Physics Letters show how to improve nanotube transistor and circuit performance with fluoropolymers September 23rd, 2014

Nanotubes help healing hearts keep the beat: Rice University, Texas Children’s Hospital patch for defects enhances electrical connections between cells September 23rd, 2014

Announcements

Future flexible electronics based on carbon nanotubes: Study in Applied Physics Letters show how to improve nanotube transistor and circuit performance with fluoropolymers September 23rd, 2014

Nanotubes help healing hearts keep the beat: Rice University, Texas Children’s Hospital patch for defects enhances electrical connections between cells September 23rd, 2014

Immune system is key ally in cyberwar against cancer: Rice University study yields new two-step strategy for weakening cancer September 23rd, 2014

Los Alamos Researchers Uncover New Properties in Nanocomposite Oxide Ceramics for Reactor Fuel, Fast-Ion Conductors: Misfit dislocations are key to transport properties across material interfaces September 23rd, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Future flexible electronics based on carbon nanotubes: Study in Applied Physics Letters show how to improve nanotube transistor and circuit performance with fluoropolymers September 23rd, 2014

Nanotubes help healing hearts keep the beat: Rice University, Texas Children’s Hospital patch for defects enhances electrical connections between cells September 23rd, 2014

Immune system is key ally in cyberwar against cancer: Rice University study yields new two-step strategy for weakening cancer September 23rd, 2014

Los Alamos Researchers Uncover New Properties in Nanocomposite Oxide Ceramics for Reactor Fuel, Fast-Ion Conductors: Misfit dislocations are key to transport properties across material interfaces September 23rd, 2014

Environment

Iranian Nano Scientists Create Flame-Resistant Polymers September 13th, 2014

NanoStruck has a High Recovery Rate on Mine Tailings: retrieval of up to 96% of Gold, 88% of Silver and 86% of Palladium September 12th, 2014

Nanostruck announces 87.6% recovery of 56 GMS/ton silver tailings samples September 12th, 2014

Boosting armor for nuclear-waste eating microbes September 12th, 2014

Water

Malvern Instruments & Aurora Water conference presentation illustrates value and cost-saving potential of on-line zeta potential in water treatment: 2014 RMSAWWA/RMWEA Joint Annual Conference, Albuquerque, New Mexico, USA September 7th – 10th September 3rd, 2014

New Nanosorbent Helps Elimination of Colorants from Textile Wastewater August 25th, 2014

Eco-friendly 'pre-fab nanoparticles' could revolutionize nano manufacturing: UMass Amherst team invents a way to create versatile, water-soluble nano-modules August 13th, 2014

PerkinElmer to Display Innovative Detection and Informatics Offerings at ACS National Meeting & Exposition Detection, Data Visualization and Analytics for Chemistry Professionals August 8th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE