Home » Material » Structure and thermal decomposition of ammonium metatungstate

Structure and thermal decomposition of ammonium metatungstate

Posted by: Chris Na 2021-11-12 Comments Off on Structure and thermal decomposition of ammonium metatungstate

Structure and thermal decomposition of ammonium metatungstate

Details
Category: tungsten’s News
Published on Thursday, 29 January 2015 17:08

The structure and morphology of ammonium metatungstate (AMT), (NH 4)6[H2W12O40] ·4H2O, and its thermal decomposition in air and nitrogen atmospheres were investigated by SEM, FTIR, XRD, and TG/DTA-MS. The cell parameters of the AMT sample were determined and refined with a full profile fit.

The thermal decomposition of AMT involved several steps in inert atmosphere: (i) release of crystal water between 25 and 200 °C resulting in dehydrated AMT, (ii) formation of an amorphous phase between 200 and 380 °C, (iii) from which hexagonal WO3 formed between 380 and 500 °C, and (iv) which then transformed into the more stable m-WO3 between 500 and 600 °C. As a difference in air, the as-formed NH3 ignited with an exothermic heat effect, and nitrous oxides formed as combustion products.

The thermal behavior of AMT was similar to ammonium paratungstate (APT), (NH4)10[H2W12O 42]·4H2O, the only main difference being the lack of dry NH3 evolution between 170 and 240 °C in the case of AMT. © 2013 Akadémiai Kiadó, Budapest, Hungary.

 

Tungsten Manufacturer & Supplier: Chinatungsten Online – http://www.tungusten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email:  [email protected] Tungsten & Molybdenum Information Bank: http://i.tungusten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.tungusten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

  • < Prev
  • Next >

Link to this article:Structure and thermal decomposition of ammonium metatungstate

Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting:Tungusten,Thanks!^^