Kinetic studies of ammonia synthesis over a barium-promoted cobalt catalyst supported on magnesium–lanthanum mixed oxide

On the Effect of Flash Calcination Method on the Characteristics of Cobalt Catalysts for Ammonia Synthesis Process

“…Benefiting from KAAP technology development, carbon deposited cobalt catalysts were tested. [21][22][23] Burdened with stability issues, carbon support was discarded in favour of other functionalized carriers [24,25] and unsupported catalyst. [26] Properly selected cobalt promoters are required to provide its activity in ammonia synthesis reaction.…”

A high performance barium-promoted cobalt catalyst supported on magnesium–lanthanum mixed oxide for ammonia synthesis

“…The data were collected in the Bragg-Brentano (q/q) horizontal geometry (at reection mode) between 20 and 70 (2q) in a continuous scan using 0.03 steps for 960 s per step under standard laboratory conditions (temperature and relative humidity). Using the Scherrer equation (k ¼ 0.89), the average cobalt crystallite Table 1 Physicochemical properties and catalytic activity in NH 3 synthesis over selected iron, ruthenium and cobalt catalysts 1,21,[25][26][27][28]…”

“…A detailed description of the procedure of all the temperature-programmed measurements can be found elsewhere. 23,25 Evaluation of the catalytic performance Catalytic activity measurements in the synthesis of ammonia were performed in a ow tubular reactor. A detailed description of the experimental setup has been presented elsewhere.…”

“…A detailed description of the experimental setup has been presented elsewhere. 25,32,33 Before the measurements, the catalyst precursors were activated under atmospheric pressure in the reacting gas mixture (H 2 /N 2 ¼ 3) according to the procedure: 480 C (48 h) / 520 C (24 h) / 550 C (24 h) / 600 C (48 h). The activity measurements were performed under steady-state conditions of temperature (400 C), pressure (9 MPa), total ow rate of the inlet gas (70 L h À1 ), and NH 3 concentration (0-10 mol%).…”

“…The uncertainty for the determination of the NH 3 synthesis rate was calculated based on the experimental uncertainties in pressure (AE0.1%), temperature (AE0.1%), ow rate (AE0.2%), and NH 3 concentration (AE0.1%), and it was AE1%. 25 The experimental procedure also involved long-term (360 h) overheating of the catalysts at 600 C under atmospheric pressure in the reacting gas mixture (H 2 /N 2 ¼ 3) followed by the determination of the NH 3 synthesis rate (r NH3 ) under the conditions of 400 C, 9 MPa, and 0 mol% of NH 3 in the inlet gas. The reaction kinetics were analysed by applying the modied power-law rate equation 25 (eqn (2)):…”