Prepn of nickel-base catalyst for decomposing ammonia

Abstract

The present invention discloses the preparation process of nickel-base catalyst for decomposing ammonia. The preparation process includes the following steps: preparing water or alcohol solution of nitrate containing Ni, Al or Zr, with assistant La or Ce being capable of being added into the solution, and preparing stoichiometric water or alcohol solution of ammonium carboanate or ammonium bicarboanate; dropping these two kinds of solution into the same container while controlling the pH of the mixed solution in 7-10; stirring to age after finishing material feeding, separating to eliminate mother liquid, washing the precipitate with deionized water, drying and roasting at 400-900 deg.c to obtain the nickel-base catalyst. The nickel-base catalyst has high catalytic activity and high stability as well as simple preparation process and low production cost.

Description

technical field

[0001] The invention relates to a preparation method of a low-temperature and high-efficiency nickel-based ammonia decomposition catalyst, and specifically provides a preparation method of a nickel-based catalyst for decomposing ammonia into hydrogen and nitrogen. Background technique

[0002] The establishment of decentralized hydrogen refueling stations is the development trend of the widespread application of hydrogen energy in the field of fuel cells in the future. In recent years, foreign countries have begun to focus on the corresponding technology research and development for the establishment of hydrogen refueling stations. Japan's Toho Gas, for example, has built a hydrogen refueling station at Aichi Laboratories to refuel fuel cell electric vehicles with hydrogen. As of 2004, the Japanese government has established eight hydrogen refueling stations in Tokyo. According to the latest literature report in 2003 (International Journal of Hydrogen Energy...

Examples

Embodiment 1

[0017] Dissolve 155g of nickel nitrate and 74g of aluminum nitrate in 500ml of deionized water to prepare a mixed solution for later use. Get stoichiometric ammonium carbonate and dissolve it in 500ml deionized water, and use it as a precipitating agent for subsequent use. The above two solutions were added dropwise into the same vessel under stirring, and the pH value of the solution was controlled to be 8. After the feed was completed, it was stirred and aged for 2 hours, centrifuged and washed with deionized water to obtain a gel. After drying at 120°C, the temperature was programmed to rise to 600°C and baked in air for 8 hours. Prepare Ni / Al with nickel oxide content of 80% 2 o 3 catalyst.

[0018] According to the above method, the feed intake is changed to 117g nickel nitrate and 147g aluminum nitrate to obtain Ni / Al with a nickel oxide content of 63%. 2 o 3 catalyst.

[0019] According to the above-mentioned method, change feeding intake into 7.8g nickel nitrate...

Embodiment 2

[0024] Dissolve 46g of nickel nitrate, 59g of aluminum nitrate, and 9g of lanthanum nitrate in 200ml of deionized water to prepare a mixed solution for later use. Get stoichiometric ammonium carbonate and dissolve it in 200ml deionized water, and use it as a precipitating agent for subsequent use. The above two solutions were added dropwise into the same vessel under stirring, and the pH value of the solution was controlled to be 8. After the feed was completed, it was stirred and aged for 6 hours, centrifuged and washed with deionized water to obtain a gel. After drying at 120°C, the temperature was programmed to rise to 600°C and baked in air for 4 hours. Prepare Ni / La-Al with nickel-aluminum atomic ratio of 1.2 and lanthanum-nickel atomic ratio of 0.22 2 o 3 catalyst.

[0025] According to the above method, the feed intake was changed to 46g of nickel nitrate, 59g of zirconium nitrate, and 11g of cerium nitrate to obtain Ni / Ce-ZrO with a nickel-aluminum atomic ratio of ...

Embodiment 3

[0031] According to the preparation method described in Example 2, ammonium carbonate was changed to ammonium bicarbonate to obtain Ni / La-Al with a nickel-aluminum atomic ratio of 1.2 and a lanthanum-nickel atomic ratio of 0.21 2 o 3 catalyst.

[0032] Take 1.0 g of the catalyst, and perform activity evaluation according to the conditions described in Example 2. Experimental results: when the ammonia gas flow rate is 333ml / min at 550°C, the ammonia gas conversion rate is 99.7%.

[0033] With Ni / La-Al gained in embodiment 2 2 o 3 Compared with the catalyst, the activity of the catalyst prepared by using ammonium bicarbonate or ammonium carbonate as the precipitating agent is equivalent. This shows that both ammonium carbonate and ammonium bicarbonate are better precipitants for the preparation of highly active nickel-based ammonia decomposition catalysts by co-precipitation.

technical field

[0001] The invention relates to a preparation method of a low-temperature and high-efficiency nickel-based ammonia decomposition catalyst, and specifically provides a preparation method of a nickel-based catalyst for decomposing ammonia into hydrogen and nitrogen. Background technique

[0002] The establishment of decentralized hydrogen refueling stations is the development trend of the widespread application of hydrogen energy in the field of fuel cells in the future. In recent years, foreign countries have begun to focus on the corresponding technology research and development for the establishment of hydrogen refueling stations. Japan's Toho Gas, for example, has built a hydrogen refueling station at Aichi Laboratories to refuel fuel cell electric vehicles with hydrogen. As of 2004, the Japanese government has established eight hydrogen refueling stations in Tokyo. According to the latest literature report in 2003 (International Journal of Hydrogen Energy...

Examples

Embodiment 1

[0017] Dissolve 155g of nickel nitrate and 74g of aluminum nitrate in 500ml of deionized water to prepare a mixed solution for later use. Get stoichiometric ammonium carbonate and dissolve it in 500ml deionized water, and use it as a precipitating agent for subsequent use. The above two solutions were added dropwise into the same vessel under stirring, and the pH value of the solution was controlled to be 8. After the feed was completed, it was stirred and aged for 2 hours, centrifuged and washed with deionized water to obtain a gel. After drying at 120°C, the temperature was programmed to rise to 600°C and baked in air for 8 hours. Prepare Ni / Al with nickel oxide content of 80% 2 o 3 catalyst.

[0018] According to the above method, the feed intake is changed to 117g nickel nitrate and 147g aluminum nitrate to obtain Ni / Al with a nickel oxide content of 63%. 2 o 3 catalyst.

[0019] According to the above-mentioned method, change feeding intake into 7.8g nickel nitrate...

Embodiment 2

[0024] Dissolve 46g of nickel nitrate, 59g of aluminum nitrate, and 9g of lanthanum nitrate in 200ml of deionized water to prepare a mixed solution for later use. Get stoichiometric ammonium carbonate and dissolve it in 200ml deionized water, and use it as a precipitating agent for subsequent use. The above two solutions were added dropwise into the same vessel under stirring, and the pH value of the solution was controlled to be 8. After the feed was completed, it was stirred and aged for 6 hours, centrifuged and washed with deionized water to obtain a gel. After drying at 120°C, the temperature was programmed to rise to 600°C and baked in air for 4 hours. Prepare Ni / La-Al with nickel-aluminum atomic ratio of 1.2 and lanthanum-nickel atomic ratio of 0.22 2 o 3 catalyst.

[0025] According to the above method, the feed intake was changed to 46g of nickel nitrate, 59g of zirconium nitrate, and 11g of cerium nitrate to obtain Ni / Ce-ZrO with a nickel-aluminum atomic ratio of ...

Embodiment 3

[0031] According to the preparation method described in Example 2, ammonium carbonate was changed to ammonium bicarbonate to obtain Ni / La-Al with a nickel-aluminum atomic ratio of 1.2 and a lanthanum-nickel atomic ratio of 0.21 2 o 3 catalyst.

[0032] Take 1.0 g of the catalyst, and perform activity evaluation according to the conditions described in Example 2. Experimental results: when the ammonia gas flow rate is 333ml / min at 550°C, the ammonia gas conversion rate is 99.7%.

[0033] With Ni / La-Al gained in embodiment 2 2 o 3 Compared with the catalyst, the activity of the catalyst prepared by using ammonium bicarbonate or ammonium carbonate as the precipitating agent is equivalent. This shows that both ammonium carbonate and ammonium bicarbonate are better precipitants for the preparation of highly active nickel-based ammonia decomposition catalysts by co-precipitation.

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