Identification Of Active Phase Research Articles

ChemInform Abstract: Understanding Co‐Mo Catalyzed Ammonia Decomposition: Influence of Calcination Atmosphere and Identification of Active Phase.

AbstractCo(en)3MoO4 as an NH3 decomposition catalyst precursor is calcined in argon or air (600 °C, 3 h) and then reduced in pure H2 (600 °C, 3 h).

Understanding Co‐Mo Catalyzed Ammonia Decomposition: Influence of Calcination Atmosphere and Identification of Active Phase

AbstractTo elucidate the effect of textural and chemical properties of catalysts and to discriminate the active phase are fundamental issues in heterogeneous catalysis, but they are often complicated by the nature of support adding a new dimension. In this work, metal amine metallate (Co(en)3MoO4) precursor was directly treated by calcination and prenitridation to understand these two issues in Co‐Mo catalyzed ammonia decomposition. The calcination atmosphere (i.e., Ar and Air) is found to remarkably affect the textural and chemical properties of catalysts, and air atmosphere is favorable for higher stable reactivity despite incomplete nitridation of the catalyst. Further prenitridation of the sample from the calcination of Co(en)3MoO4 under air gives rise to higher catalytic activity, and Co3Mo3N is suggested as the dominant active phase of Co‐Mo catalysts. The insights revealed here shed new light on the design of Co‐Mo catalysts for ammonia decomposition.

Comparison of clinical examination with orbital MRI evaluation in patients with thyroid orbitopathy - do we need imaging and when?

The frequency of Graves’ orbitopathy (GO) in patients with Graves’ disease (GD) depends on the method of assessment. Diagnosis based on clinical symptoms is made in about 30-50% patients, more often (70%) after ophtalmological examination with evaluation of intraocular pressure, whereas MRI reveals GO in up to 90%. Proper identification of active phase of the disease is crucial.