Posts Tagged ‘catalyst’
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October 28th, 2009
Using plasmons to study gold catalysts
Some nice work described here on Physics World, using plasmons to study gold catalyst activity…..
UPDATE – Oops! Its just been pointed out that although gold was used in the experimental technique the catalyst was actually platinum.
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July 10th, 2009
Au-based die attach materials
The issues relating to the use of gold-based alloys as die attach materials in the electronic packaging industry is highlighted by Anwar Mohammed from Infineon Technologies in Solid State Technology. He writes:
“To keep up with demanding power requirements, some savvy companies rely on eutectic attach materials such as AuSn and AuSi for die attaching to obtain superior thermal performance. The die attach temperatures are much higher relatively: ~320°C for AuSn, and ~420°C for the AuSi; but the thermal conductivity is significantly better with AuSn performing at ~70W/mK and AuSi performing at >150W/mK. The disadvantage of this approach is that it is a very tricky and sensitive process with a narrow processing window that needs to be monitored carefully.”
The reason I found this interesting (other than because it explains why Au-based materials are useful in die attach applications) is that there are direct similarities with gold-based catalysts. Like the eutectics described above, these catalysts have significant performance benefits in many reactions (selectivity, activity), but applications have been limited due to processing concerns. The problems in ‘processing’ can be related to either making the catalysts or operating them under practical conditions, where the process window may be limited. Thankfully things are now progressing well. Gold catalysts can be successfully manufactured and purchased from the likes of 3M, Strem Chemicals, AuTEK and Nanostellar (automotive) and there are applications where they are able to operate under a suitable range of processing conditions.
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July 8th, 2009
Next issue of Gold Bulletin now available!!
Hi everyoneIt’s here at last, Issue 42(2) of Gold Bulletin.
We have an issue bursting with lots of gold news and science and a superb Guest Editorial from Prof James (Jim) Johnstone from Victoria University of Wellington New Zealand.
We have all the lastest information about Gold 2009 ; the Keynote presentations , the opening Plenary presentations and all the info on the main conference sessions
We have seven wonderful scientific papers from a range of disciplines including Metallurgy, Catalysis, Analytical and also Nanotechnolgy. Also a book review of Mark Grimwade’s Introduction to Precious Metals – Metallurgy for Jewellers and Silversmiths.
Also our regular features of Highlights from Recent Literature and a summary of Calendar Events comming up in the near future.
Hope you enjoy it. Let me know what you think. I always like to hear your views.
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June 15th, 2009
New catalyst distribution agreement
It is excellent news that Strem Chemicals, the manufacturer of specialty chemicals for research and development, has now formally announced that it has entered into a distribution agreement with Mintek for their gold catalysts developed through Project AuTEK. The AUROliteTM gold catalysts perform in a variety of applications, such as gas phase CO oxidation, and may be used in respiratory protection devices..
“In terms of low temperature CO oxidation our catalysts outperform the current employed Hopcalite and PGM catalyst technologies, furthermore we see a bright future for their use in liquid phase oxidations and other industrial relevant reactions”, said Jason McPherson, Engineer at Project AuTEK and guest blogger on this website.
Other applications that have been demonstrated include the low temperature oxidation of methane, the selective oxidation of D-lactose to D-lactobionic acid and the aerobic oxidation of aldehydes to esters among others.
Strem will be offering 3 varieties of the AUROliteTMline of gold catalysts, with a 1% loading of gold on aluminum oxide, titanium dioxide and zinc oxide supports. Each catalyst offered will be “commercial grade” as AuTEK has already scaled up its production capacity. The gold itself is deposited on the support via a proprietary process that yields gold nano crystallites of about 2-3nm.
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June 10th, 2009
AuTEK at 21NAM
Its now day 3 of the 21NAM conference and AuTEK encourages all participants who are interested in Gold Catalysis to stop by the joint World Gold Council / AuTEK stand. AuTEK is excited to announce that the AUROliteTM range of materials are available from STREM Chemicals Inc. who also have a stand at 21NAM. The specific materials on offer are:
1wt% Au/Al2O3 – approx. 1.2 mm dia. × 5 mm (avg) extrudates – Strem catalogue number: 79-0160
1wt% Au/TiO2 – 1.5 mm dia. × 5 mm (avg) extrudates – Strem catalogue number: 79-0165
1wt% Au/ZnO – approx. 1-2 mm dia. granulate – Strem catalogue number: 79-0170
To obtain a quote and place an order please see:
www.strem.com or email: order@strem.com
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June 10th, 2009
Reducing Power Station Pollution
The removal of mercury contamination from flue gas streams in coal fired power stations is a major challenge in the US. A number of power plant trials are underway using the most promising technologies so far developed. One such technology is based on the use of precious metal catalysts.
Most forms of mercury can be easily removed from flue gas streams via physical processing, but some forms need to be oxidised before removal and this is the role that catalysts play. Previous research has looked at the ability of a number of metal based catalysts to do this, of which gold based systems have proven to be one of the most promising in initial screening. Gold has a high conversion level which is maintained over longer periods of time than alternative materials, of which most show a decrease in activity over time.
World Gold Council and Queen’s University, Belfast, today announced a new research collaboration to develop a gold-based catalyst that will remove mercury contamination from flue gas streams in coal fired power stations. The research team, led by Professor Hardacre at Queen’s University, Belfast, aims to develop new catalysts which have the potential to provide higher activity and stability. This research aims to develop a system that will circumvent the problems associated with existing technology, making catalysts more effective and long-lasting. It will also investigate a method by which the catalyst may be reactivated after use.
Each year World Gold Council provides financial support, via its GROW (Gold Research Opportunities Worldwide) programme, to a limited number of research and feasibility studies aimed at uncovering potential new industrial uses for gold. For more information about GROW see here.
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June 9th, 2009
Gold-copper, the new catalyst?
Is gold-copper the new gold-palladium?
The use of gold-palladium alloys in catalysis is well established. These bi-metallic catalysts are routinely used in the production of vinyl acetate monomer (VAM) by the large chemical companies (see herefor a bit more detail). Many of the promising new industrial applications for gold in catalysis are aslo based on these alloys eg direct production of hydrogen peroxide. But are other bi-metallic systems also worth looking at? This new paper published in the Royal Society of Chemistry’s journal Chemical Society Revews, says so.UPDATE – What a coincidence. Today at the 21st NAM conference, I’ve just seen work presented by researchers from Penn State describing the benefits of gold-copper alloy electrocatalysts for direct sodium borohydride fuel cells.
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June 3rd, 2009
21st NAM event
Here’s an invitation for next week……..Those of you in the catalysis field who are planning to attend the 21st NAM
should come and say ‘hello’ at the World Gold Council stand (or ‘booth’ if you are American!). We started exhibiting at the NAM events back in 2004 and have found them to be the best of all the catalysis events – strong attendance by industrialists is a noticeable feature. At the event, which is taking place in San Francisco, we will be exhibiting with Mintek, Strem, Nanostellar and 3M. More about each of these next week…… -
May 22nd, 2009
Gold catalyst demand predicted to grow
This new market report ‘World Nanocatalysts Market’ has a section entitled ‘Industrial demand for gold seen rising’. The exent to which this statement is based on hard numbers is not clear, but it looks like good news……
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May 14th, 2009
Beefing-up the Activity and Durability of Gold-Catalysed Low-Temperature Water-Gas Shift Reaction (WGSR)
In a paper entitled ‘Investigation on gold dispersion of Au/ZrO2 catalysts and activity in the low-temperature WGS reaction’, F Zane, V Trevisan, F Pinna, M Signoretto and F Menegazzo, of the Dipartimento di Chimica, Universita Ca Foscari, Dorsoduro, and Consorzio INSTM-UdR Venezia, Italy, Appl Catal B:Env, 2009, 89(1-2), 303 – 308, sulfated zirconia has been shown to have higher activities than zirconia itself when used as a support for gold for the low-temperature WGS reaction (see also patent by A Kuperman and ME Moir of Chevron, California, USA, WO Patent 2005/005032, which claims unusually good durability for such catalysts):
CO + H2O -> H2 + CO2
The sulfated catalysts promote better dispersion of the gold nanoparticles on the support rather than act as promoters for the gold active phase. Results include demonstration of a good relationship between catalytic activity and chemisorption data.
This work will have important commercial implications in providing quantity hydrogen supplies in the future.
Richard Holliday
Tricia Harris
Jason McPherson
David Thompson
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