Space-confined preparation of high surface area tungsten oxide and tungsten nitride inside the pores of mesoporous silica SBA-15

作者：Meyer Simon; Beyer Hans; Koehler Klaus; Jensen Annemette Hindhede; Christensen Erik; Bjerrum Niels J

来源：Microporous and Mesoporous Materials, 2015, 211: 147-151.

DOI：10.1016/j.micromeso.2015.03.003

• High surface area
• Mesoporous tungsten oxide
• Tungsten nitride
• Space-confined preparation

For the direct preparation of high surface area nitride materials, a lack of suitable precursors exists. Indirect preparation by gas phase nitridation (e.g. by ammonia) requires high temperatures and often results in sintering. The present work demonstrates that the space-confined preparation of W2N inside the pores of ordered mesoporous silica SBA-15 offers a possibility to reduce sintering phenomena and thus to obtain smaller particles, porous structures and a higher surface area material. The preparation was pursued in a two-step approach. First, WO3 was introduced into the channels of SBA-15 and second, ammonolysis was conducted for its conversion to W2N. When performed in the presence of the exo-template, SBA-15 acts as a stabilizer and small W2N particles (6-7 nm) with a high specific surface area (40 m(2) g(-1)) are obtained after template removal. When the template is, however, removed before nitridation, it cannot stabilize the W2N particles and enhanced sintering occurs.

• 出版日期2015-7-15