Preparation of nano-flaky iron-doped nickel phosphide and nitrogen reduction reaction (NRR) application

Abstract

In view of the heavy demand for ammonia and the harsh reaction condition and low conversion rate of a Haber-Bosch process, simple preparation of the ammonia becomes a major problem of development of the present world, and therefore, the study of achieving nitrogen reduction ammonia through electrolysis of an electrolyte with saturated nitrogen at the normal temperature and normal pressure is paidmuch attention. The invention provides a preparation method of nano-flaky iron-doped nickel phosphide nano-powder and application of the nano-flaky iron-doped nickel phosphide nano-powder to a nitrogen reduction reaction (NRR). The preparation method comprises the steps: firstly, a specific proportion of iron source reagent and nickel source reagent are added into a reaction solution, a heating reaction is conducted, and iron-nickel precursor nano-powder is obtained; and then the iron-nickel precursor nano-powder is placed into a tube furnace at the specific nitrogen flow rate to be subjectedto a phosphorization reaction, and finally the nano-flaky iron-doped nickel phosphide nano-powder is obtained. The nano-flaky iron-doped nickel phosphide nano-powder shows excellent catalytic activityin the field of the NRR, the ammonia yield under minus 0.3 V (relative to a standard hydrogen electrode) reaches up to 70.6 [mu]g h<-1> mg<cat.><-1>, and the Faradic efficiency reaches 6.5%.

Description

technical field

[0001] The invention relates to the field of preparation and application of inorganic nano-powders, in particular to a method for preparing nano-flaky iron-doped nickel phosphide nano-powders based on a hydrothermal method and its application in the field of electrocatalytic nitrogen reduction. Background technique

[0002] With the development of science and technology, people's demand and dependence on energy are getting higher and higher, and the development of new energy and energy storage materials has attracted much attention. Ammonia acts as an efficient energy carrier (17.8 % hydrogen density by weight) and is easily transportable without CO2 emissions. Furthermore, with the dramatic increase in population, the world today requires an ever-increasing need for fertilizers. The Haber-Bosch method is currently a large-scale industrial application of ammonia production technology, and more than 500 tons of ammonia are prepared and applied every year, whi...

Examples

Embodiment 1

[0019] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Next, ferric nitrate nonahydrate (0.0808 g, 0.2 mmol) and nickel nitrate hexahydrate (0.2908 g, 1.0 mmol) were added in sequence, stirred for 1 h and transferred to a polytetrafluoroethylene liner. After sealing the hydrothermal autoclave, it was kept in an oven at 120 °C for 36 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0020] Step 2: Take 50 mg iron-nickel precursor nano-powder and 4 g sodium hypophosphite and place them in a tube furnace under nitrogen atmospher...

Embodiment 2

[0031] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Next, ferric chloride hexahydrate (0.1622 g, 0.6 mmol) and nickel chloride hexahydrate (0.8557 g, 3.6 mmol) were added in sequence, stirred for 1 h and then transferred to a polytetrafluoroethylene liner. After sealing the hydrothermal autoclave, it was kept in an oven at 140 °C for 30 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0032] Step 2: Take 50 mg iron-nickel precursor nano-powder and 1.5 g sodium hypophosphite in a tube furnace, 400 °C under nitrogen atmosph...

Embodiment 3

[0043] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Add ferric sulfate (0.1599 g, 0.4 mmol) and nickel acetylacetonate (0.5138 g, 2.0 mmol) in turn, and transfer them to a polytetrafluoroethylene liner after stirring for 1 h. After sealing the hydrothermal autoclave, it was kept in an oven at 150 °C for 22 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0044] Step 2: Take 50 mg iron-nickel precursor nano-powder and 3 g sodium hypophosphite in a tube furnace, 500 o C calcined for 2 h, the heating rate was 2 o C / min, th...

technical field

[0001] The invention relates to the field of preparation and application of inorganic nano-powders, in particular to a method for preparing nano-flaky iron-doped nickel phosphide nano-powders based on a hydrothermal method and its application in the field of electrocatalytic nitrogen reduction. Background technique

[0002] With the development of science and technology, people's demand and dependence on energy are getting higher and higher, and the development of new energy and energy storage materials has attracted much attention. Ammonia acts as an efficient energy carrier (17.8 % hydrogen density by weight) and is easily transportable without CO2 emissions. Furthermore, with the dramatic increase in population, the world today requires an ever-increasing need for fertilizers. The Haber-Bosch method is currently a large-scale industrial application of ammonia production technology, and more than 500 tons of ammonia are prepared and applied every year, whi...

Examples

Embodiment 1

[0019] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Next, ferric nitrate nonahydrate (0.0808 g, 0.2 mmol) and nickel nitrate hexahydrate (0.2908 g, 1.0 mmol) were added in sequence, stirred for 1 h and transferred to a polytetrafluoroethylene liner. After sealing the hydrothermal autoclave, it was kept in an oven at 120 °C for 36 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0020] Step 2: Take 50 mg iron-nickel precursor nano-powder and 4 g sodium hypophosphite and place them in a tube furnace under nitrogen atmospher...

Embodiment 2

[0031] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Next, ferric chloride hexahydrate (0.1622 g, 0.6 mmol) and nickel chloride hexahydrate (0.8557 g, 3.6 mmol) were added in sequence, stirred for 1 h and then transferred to a polytetrafluoroethylene liner. After sealing the hydrothermal autoclave, it was kept in an oven at 140 °C for 30 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0032] Step 2: Take 50 mg iron-nickel precursor nano-powder and 1.5 g sodium hypophosphite in a tube furnace, 400 °C under nitrogen atmosph...

Embodiment 3

[0043] Step 1: Take a 50 mL hydrothermal reaction kettle for laboratory use. The hydrothermal reaction kettle has a stainless steel shell and a polytetrafluoroethylene liner. Add 40 mL of deionized water to a 50 mL polytetrafluoroethylene liner, add trisodium citrate (0.0029 g, 0.01 mmol) and urea (0.0841 g, 1.4 mmol) and stir for 30 min to form a clear and transparent solution, then continue stirring Add ferric sulfate (0.1599 g, 0.4 mmol) and nickel acetylacetonate (0.5138 g, 2.0 mmol) in turn, and transfer them to a polytetrafluoroethylene liner after stirring for 1 h. After sealing the hydrothermal autoclave, it was kept in an oven at 150 °C for 22 h. After natural cooling, deionized water and absolute ethanol were used to centrifugally wash and dry in vacuum to obtain iron-nickel precursor nanopowder.

[0044] Step 2: Take 50 mg iron-nickel precursor nano-powder and 3 g sodium hypophosphite in a tube furnace, 500 o C calcined for 2 h, the heating rate was 2 o C / min, th...