NixPy electrocatalyst and preparation method thereof

Abstract

The preparation method comprises the following steps: firstly, dissolving a carbon carrier and a nickel source in deionized water, and uniformly mixing the carbon carrier and the nickel source in an ultrasonic manner to obtain dark green turbid liquid; drying the dark green turbid liquid to obtain a dark green solid; roasting and screening the dark green solid to obtain a precursor with nickel oxide; putting the precursor into a quartz tube, putting the quartz tube into a tubular furnace, introducing hydrogen phosphide gas into the tubular furnace, and phosphating to obtain a NixPy electrocatalyst; the method is low in preparation cost, short in time and simple in process, the problem of yellow phosphorus tail gas emission is effectively solved, and production of green energy is promoted; the electrocatalyst has a good application prospect in the field of hydrogen production through electrocatalytic water decomposition.

Description

Technical Field

[0001] The present invention relates to the technical field of electrocatalysts, and in particular to a Ni x P y Electrocatalyst and method for preparing the same. Background Art

[0002] The efficient production of high-purity hydrogen is of great significance in energy technology; for example, the economical production of hydrogen fuel could make CO2-free aviation possible, provided that hydrogen is produced through carbon-free technologies. Compared with methane reforming and coal gasification, electrocatalytic water splitting offers an environmentally friendly way to produce hydrogen. It can also efficiently convert and store intermittent renewable electricity, such as wind and solar power. The electrolysis of water consists of two major half-reactions, specifically the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Efficient and stable catalysts are required to reduce the activation energy and thus accelerate the kinetics. Traditionally, noble metal catalysts have been used, so industrial electrocatalytic water splitting is greatly limited by the low availability and high cost of these catalysts. Therefore, it is very important to develop cheap and efficient non-noble metal catalysts for these reactions. Transition metal nickel phosphide (NiP) is a promising candidate for the electrocatalytic water splitting reaction. 2 P) electrocatalysts have excellent conductivity, abundant active sites and low cost, and have been proven to be an ideal choice to replace scarce precious metal platinum and platinum-based catalysts as an ideal choice for electrocatalytic water splitting and hydrogen production. x P y The preparation of nickel oxide is mainly achieved by heating phosphorus-containing chemicals such as sodium hypophosphite and red phosphorus at a certain temperature to produce phosphine gas. The preparation process is relatively complicated and costly. Therefore, it is still urgent to develop a simple, efficient and low-cost method to integrate electrocatalysts supported by phosphides on porous carbon.

[0003] Phosphine is a flammable, explosive and highly biologically toxic gas. If it is discharged into the atmosphere without treatment, it will seriously threaten human health and the ecological environment, and will also lead to an indirect greenhouse effect. The tail gas emitted by the phosphorus chemical industry is one of the main sources of phosphine in the atmosphere. The concentration of phosphine in the tail gas emitted by the yellow phosphorus production plant is about 1000ppm. In order to protect human health and the environment, the PH in the tail gas must be 3 Conduct effective processing;

[0004] Therefore, there is an urgent need for a method that is beneficial to PH 3 The efficient adsorption of NiO2 produces an electrocatalyst after adsorption and phosphation, avoiding the secondary pollution of the deactivated adsorbent and being beneficial to the production of green energy. x P y Electrocatalyst and preparation method thereof are used to solve the above technical problems. Summary of the invention

[0005] The object of the present invention is to provide a Ni x P y An electrocatalyst and a preparation method thereof, wherein a carbon carrier and a nickel source are impregnated, ultrasonically stirred, dried, and calcined to prepare a precursor, and the electrocatalyst is prepared by the phosphating reaction of the precursor with phosphine. The electrocatalyst is synthesized while achieving efficient removal of phosphine in tail gas. This is a simple, low-cost method for synthesizing transition metal nickel phosphide.

[0006] The present invention provides a Ni x P y The method for preparing an electrocatalyst comprises the following steps:

[0007] S1: dissolving the carbon support and the nickel source in deionized water and mixing them evenly to obtain a dark green suspension;

[0008] S2: drying the dark green suspension to obtain a dark green solid;

[0009] S3: calcining, crushing and screening the dark green solid to obtain a precursor having nickel oxide;

[0010] S4: placing the precursor in a quartz tube, placing it in a tube furnace, introducing yellow phosphorus tail gas into the tube furnace, and obtaining Ni after phosphating. x P y of electrocatalysts.

[0011] In the present invention, the yellow phosphorus tail gas contains phosphine gas, which reacts with the precursor to obtain Ni x P y of electrocatalysts.

[0012] Preferably, the mass ratio of the carbon support: nickel source: deionized water is 2.457:1:40.

[0013] Preferably, the carbon carrier is any one of activated carbon (AC), urea-doped activated carbon (AC-N), glucose-doped activated carbon (AC-G), urea and glucose-doped activated carbon (AC-GN), and the nickel source is nickel nitrate.

[0014] Preferably, in S2, the drying temperature is 60-150° C. and the drying time is 5-12 hours.

[0015] Preferably, in S3, the roasting tool is a tubular furnace, the roasting temperature is 300-500° C., the heating rate is 5-10° C., and the roasting time is 1-3 hours.

[0016] Preferably, in S3, the sieve size selected for the screening is 40-60 mesh, and the loading amount of nickel oxide in the precursor is 1-60 wt%.

[0017] Preferably, in S4, the concentration of phosphine introduced is 800-1200 ppm, the phosphating temperature is 350-390° C., the phosphine flow rate is 50-200 mL / min, and the phosphating time is 60-360 min.

[0018] Preferably, the above Ni x P y Preparation method of electrocatalyst Ni x P y Electrocatalyst.

[0019] Preferably, the Ni x P y For you 2 P or Ni 5 P 4 .

[0020] The present invention discloses the following technical effects: The present invention provides a Ni x P y The electrocatalyst and its preparation method have low preparation cost, short preparation time and simple process, which effectively solves the problem of yellow phosphorus tail gas emission and promotes the production of green energy; the electrocatalyst has good application prospects in the field of electrocatalytic water decomposition and hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 The XRD diagram of the adsorbent after adsorbing phosphine at different reaction temperatures in Example 1 of the present invention;

[0023] Figure 2 The adsorption performance diagram of the precursors prepared in Examples 2 to 4 of the present invention when using different carriers;

[0024] Figure 3 A comparison chart of hydrogen evolution performance of the phosphating materials in Examples 2 to 4 of the present invention;

[0025] Figure 4 This is a graph showing the adsorption performance of materials with different nickel loading amounts in Example 6 of the present invention;

[0026] Figure 5 This is a graph showing the hydrogen evolution performance of materials with different nickel loading amounts in Example 6 of the present invention; DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The present invention provides a low-cost Ni 2 P or Ni 5 P 4 The invention discloses a method for preparing an electrocatalyst, which utilizes highly biologically toxic phosphine gas to phosphate nickel oxide supported on porous carbon. The electrocatalyst thus formed has broad application prospects in the field of electrocatalytic water decomposition and hydrogen production.

[0030] Embodiment 1:

[0031] A Ni x P y A method for preparing an electrocatalyst, the method comprising the following steps:

[0032] First, 2.457 g of nickel nitrate is added to a beaker containing 40 ml of deionized water, and ultrasonic treatment is performed for 30 minutes under the conditions of an ultrasonic frequency of 40 Hz and an output power of 100 W, and then dried at 80° C. to form a dark green solid. The dark green solid is then placed in a tubular furnace, heated to 400° C. at a heating rate of 10° C. / min, and calcined for 2 hours. The black solid particles obtained by calcination are crushed and sieved with a 40-mesh to 60-mesh sieve, and the 40-60-mesh particles are collected as precursor NiO.

[0033] 0.05 g of the obtained precursor was placed in a quartz tube, and the phosphating temperatures were 360°C, 370°C, 380°C, and 390°C, respectively. Phosphine with a concentration of 1000 ppm was introduced into the quartz tube at a flow rate of 100 mL / min. After phosphating for 105 min, Ni-containing x P y (x=2,5,y=1,4) electrocatalyst, named Ni x P y -X, where X represents different phosphating temperatures, such as Figure 1 shown.

[0034] Example 2

[0035] Nickel nitrate and commercial activated carbon powder (AC) were added into a beaker containing 40 ml of deionized water at a mass ratio of 2.457:1, and ultrasonic treatment was performed for 30 min. The other conditions were the same as in Example 1. The black solid particles obtained by calcination were crushed and sieved with a 40-60 mesh sieve, and the particles with a 40-60 mesh were collected as the precursor NiO / AC. The nickel loading in the precursor was 50 wt%.

[0036] 0.05 g of the obtained precursor was placed in a quartz tube, and the phosphating temperature was controlled to be 380°C by a tube furnace. 1000 ppm phosphine was passed into the quartz tube at a flow rate of 100 mL / min. Ni was prepared after phosphating for 105 min. x P y The electrocatalyst supported on porous carbon is named Ni x P y / AC.

[0037] Example 3

[0038] The AC in Example 2 was modified by adding urea in an equal proportion to AC to obtain AC-N as a carbon carrier. The other parts were the same as those in Example 1 and were named Ni x P y / AC-N.

[0039] Example 4

[0040] AC in Example 2 was modified by adding glucose in an equal ratio to AC to obtain AC-G as a carbon carrier. The rest was the same as in Example 1 and was named Ni x P y / AC-G.

[0041] Example 5

[0042] AC in Example 2 was modified by adding glucose and urea in equal proportions to AC to obtain AC-GN as a carbon carrier. The rest was the same as in Example 1 and was named Ni x P y / AC-GN.

[0043] Example 6

[0044] The mass ratio of nickel nitrate to commercial activated carbon powder in Example 2 was modified to 0.491:1, 0.983:1, 1.474:1, and 1.966:1, respectively, to prepare precursors with nickel loadings of 10wt%, 20wt%, 30wt%, and 40wt%, respectively. The rest was the same as in Example 1, to prepare Ni-containing precursors with different nickel contents. x P y of electrocatalysts.

[0045] In the specific preparation process, as the phosphating time increases and as the P content increases, Ni2 P will transform into Ni 5 P 4 .

[0046] The batch number of commercial activated carbon powder product is Tianjin Zhiyuan Chemical Reagent Co., Ltd. 2023061713.

[0047] It can be seen from the above embodiments and experimental examples that the Ni-containing x P y The preparation time of electrocatalysts is relatively short, the raw materials are cheap and easy to obtain, they are not restricted by time and region, and no side reactions will occur. They have good application prospects in the fields of photoelectrocatalytic water decomposition to produce hydrogen, photocatalytic degradation of organic pollutants, etc.

[0048] The invention uses potassium permanganate solution and sodium hydroxide solution to absorb the tail gas after the phosphating reaction in sequence.

[0049] The present invention Figure 1 It can be seen that at 380°C, the formation of nickel phosphide is more obvious;

[0050] from Figure 2 It can be seen that when the commercial activated carbon is modified with urea and glucose in a mass ratio of 1:1, its adsorption performance is better than that of the material modified with only urea or glucose, and the adsorption efficiency of Ni50% / AC-GN phosphine is 99.1%, indicating that the joint modification of urea and glucose enhances the adsorption performance of the material;

[0051] from Figure 3 It can be seen that different modified carriers have an impact on the hydrogen evolution performance of the phosphated material; by comparison, the hydrogen evolution performance of the carrier modified with a mass ratio of urea and glucose of 1:1 after phosphating is better than that modified with only urea or glucose, and its overpotential is 262mV.

[0052] from Figure 4 Commercial activated carbon powder was used as a carrier to explore the optimal conditions for nickel loading. It can be seen from the figure that when the nickel loading is 50%, the adsorption effect of phosphine is as good as 96.8%.

[0053] from Figure 5 It can be seen that the hydrogen evolution performance of nickel with a loading of 50% is also better than that of other loadings, and its overpotential is 311mV.

[0054] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0055] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A Ni x P y A method for preparing an electrocatalyst, characterized in that: The following steps are involved: S1: dissolving the carbon support and the nickel source in deionized water and mixing them evenly to obtain a dark green suspension; S2: drying the dark green suspension to obtain a dark green solid; S3: calcining, crushing and screening the dark green solid to obtain a precursor having nickel oxide; S4: placing the precursor in a quartz tube, placing it in a tube furnace, introducing yellow phosphorus tail gas into the tube furnace, and obtaining Ni after phosphating. x P y of electrocatalysts.

2. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: The mass ratio of the carbon support: nickel source: deionized water is 2.457:1:

40.

3. A Ni according to claim 2 x P y A method for preparing an electrocatalyst, characterized in that: The carbon carrier is any one of activated carbon, urea-doped activated carbon, glucose-doped activated carbon, and activated carbon doped with urea and glucose, and the nickel source is nickel nitrate.

4. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: In S1, ultrasonic mixing is performed to achieve uniform mixing, the ultrasonic frequency is 40-60 Hz, the output power is 100-120 W, and the ultrasonic mixing time is 40-50 min.

5. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: In S2, the drying temperature is 60-150°C and the drying time is 5-12 hours.

6. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: In S3, the baking tool is a tubular furnace, the baking temperature is 300-500°C, the heating rate is 5-10°C, and the baking time is 1-3h.

7. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: In S3, the sieve size selected for sieving is 40-60 mesh, and the loading amount of nickel oxide in the precursor is 1-60 wt%.

8. A Ni according to claim 1 x P y A method for preparing an electrocatalyst, characterized in that: In the S4, the concentration of the introduced phosphine is 800-1200 ppm, the phosphating temperature is 350-390° C., the phosphine flow rate is 50-200 mL / min, and the phosphating time is 60-360 min.

9. A Ni x P y An electrocatalyst characterized in that Using any one of claims 1 to 8 of Ni x P y The electrocatalyst is prepared by a preparation method.

10. A Ni according to claim 9 x P y An electrocatalyst characterized by: The Ni x P y It is Ni2P or Ni5P4.

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