One minute synthesis for microporous materials

AlPO4-5 has been commercialised as a vapour adsorbent for refrigerators

Researchers in Japan have developed the fastest known synthetic route for preparing crystalline microporous solids. The method is currently being scaled-up to meet the increasing demand for these versatile materials in industrial applications.

Crystalline microporous solids are an important class of inorganic material that impact our everyday lives. Their ordered structures contain arrays of channels and voids several nanometres across, enabling them to selectively and reversibly absorb molecules based on their shapes and sizes. This has led to their widespread use as catalysts, molecular sieves and gas sensors. Research into their potential use as hydrogen storage materials for mobile energy applications is also ongoing.

However, microporous solids often crystallise slowly and typically require several hours to several weeks of hydrothermal treatment to achieve satisfactory yields, limiting their applications on industrial scales. Now, a collaborative effort from the University of Tokyo and the Mitsubishi Chemical Group has led to an ultra-fast method for preparing the aluminophosphate AlPO4-5. A combination of rapid heating and crystal seeding completes the synthesis within one minute.

The tubular reactor heats up very quickly

The team use a cheap stainless steel tubular reaction vessel that provides a very high surface area to volume ratio. ‘It takes only several tens of seconds to reach the target temperature in our tubular reactor compared to several hours for a conventional autoclave. This fast heating induces a higher crystal growth rate,’ says Tatsuya Okubo, from the University of Tokyo, who led the study. Adding a seed crystal to the reaction was also found to dramatically decrease the time required for crystallisation by bypassing the energy barrier for spontaneous nucleation of initial particles. Okubo’s team have applied this technique to develop a low cost continuous flow process with very high throughput, to meet industrial requirements for these materials.

‘Besides reducing the manufacturing cost of powders, fast growth can lead to rapid membrane synthesis and even provide a better mechanistic picture of crystallisation,’ says Prabir Dutta, a microporous materials expert at Ohio State University in Columbus, US. He adds that ‘the challenge is to see if this method can be generalised for the growth of other materials, especially the industrially important aluminosilicates’.

Related Content

Reducing the cost of oxygen enrichment

2 May 2012 Research

news image

A synthesis developed by UK scientists could reduce the cost of studying porous materials by oxygen NMR

Reducing the cost of oxygen enrichment

6 April 2012 Research

news image

A synthesis developed by UK scientists could reduce the cost of studying porous materials by oxygen NMR

Most Read

US government science institute's one time police chief linked to campus meth lab

31 July 2015 News and Analysis

news image

Explosion injuring a member of the National Institute of Standards and Technology's security force uncovered methamphetamine ...

Antifreeze polymer protects cells as they thaw

29 July 2015 Research

news image

Simple synthetic polymer found to enhance cryopreservation of red blood cells by inhibiting ice crystal growth

Most Commented

Philae poses comet chemistry conundrum

30 July 2015 Research

news image

Historic mass spectra find 67P carries precursors to key biomolecules, but instruments detect different ones

Butterfly population collapse prompts lawsuit against EPA

5 March 2015 News and Analysis

news image

US agency criticised for failing to investigate link between glyphosate and the dwindling monarch butterfly population