Formation Mechanism for Zr2S

[SGV]

Zirconium oxychloride octahydrate (ZrOCl₂.8H₂O) and thiourea (CH₄N₂S) to form Zirconium Sulphide in Zr₂S phase.
Can anybody help with the transformation mechanism and balance the equation?

[ChenBeier]

Do you mean ZrS₂, do you?
Zirkonium is four valent, not one valent.

ZrOCl₂ × 8 H₂O + 2 (NH₂)₂CS => ZrS₂ + 4 NH₃ + 2 CO₂ + 5 H₂O + 2 HCl

[SGV]

I meant Zr₂S (examples - Ag₂s and Cu₂s)

[saun]

The formation of zirconium sulfide (Zr₂S) from zirconium oxychloride octahydrate (ZrOCl₂·8H₂O) and thiourea (CH₄N₂S) involves a series of chemical reactions, including hydrolysis, decomposition, and reduction. Below is a proposed mechanism and the balanced chemical equation for the process.

Proposed Mechanism:

• Hydrolysis of Zirconium Oxychloride:

ZrOCl₂·8H₂O undergoes hydrolysis in water to form zirconium hydroxide (Zr(OH)₄) and hydrochloric acid (HCl):
ZrOCl₂⋅8H₂O→Zr(OH)₄+2HCl+7H₂O

• Decomposition of Thiourea:

Thiourea decomposes upon heating to release hydrogen sulfide (H₂S), which acts as the sulfur source for zirconium sulfide formation:
CH₄N₂S→H₂S+HCN+NH₃

• Reaction of Zirconium Hydroxide with Hydrogen Sulfide:

Zirconium hydroxide reacts with hydrogen sulfide to form zirconium sulfide (Zr₂S) and water:
2Zr(OH)₄+3H₂S→Zr₂S+8H₂O


Balanced Overall Equation:

Combining the above steps, the overall balanced equation for the formation of Zr₂S is:
2ZrOCl₂⋅8H₂O+3CH₄N₂S→Zr₂S+6HCl+3HCN+3NH₃+23H₂O

Key Points:

• Thiourea acts as a sulfur source by decomposing to H₂S.

• Zirconium oxychloride hydrolyzes to form zirconium hydroxide, which then reacts with H₂S to produce Zr₂S.

• The reaction is typically carried out under controlled heating conditions to ensure complete decomposition and reaction.

[ChenBeier]

Zirkonium is not one valent. Zr₂S is not existing.
ZrS₂ is existing. 4 valent.

A lot of errors in the equations

ZrOCl₂⋅8H₂O→Zr(OH)₄+2HCl+7H₂O not balanced
Left 9 O right 11 O
Left 16 H right 20 H

CH₄N₂S→H₂S+HCN+NH₃ not balanced
Left 4 H right 6 H

2Zr(OH)₄+3H₂S→Zr₂S+8H₂O not balanced

Left 14 H right 16 H
Left 3 S right 1 S

2ZrOCl₂⋅8H₂O+3CH₄N₂S→Zr₂S+6HCl+3HCN+3NH₃+23H₂O not balanced
Left 10 O right 23 O
Left 4 Cl right 6 Cl
Left 28 H right 64 H



Show me a link or book where Zr₂S is published.

[ChenBeier]

I meant Zr₂S (examples - Ag₂s and Cu₂s)

Copper and silver in first group, zirconium in fourth group of transition metals in PSE.

[SGV]

Hello ChenBeier,
I have this doi, please refer below!
10.1016/0022-5088(88)₉₀₂₀₀-7
The reaction of zirconium with sulphur can form a variety of sulphide phases such as ZrS, ZrS₂, ZrS₃, Zr₂S₃, ZrS₄, and ZrOS based on the reaction parameters, so there will be a possibility for Zr₂S right?
if it is possible to form Zr₂S, what is the mechanism?
The answers will be much appreciated!
Thank you!

[ChenBeier]

I don't know what this number 10.1016/0022-5088(88)₉₀₂₀₀-7 means.
I don't think that beside ZrS and ZrS₂ any other sulfides existing under normal conditions.

You would need a redox reaction. Thiourea I think can not do it.

The reaction with water is:

(NH₂)₂CS + H₂O =>(NH₂)₂CO + H₂S Thiourea change to Urea and hydrogen sulfide

(NH₂)₂CO + H₂O => 2 NH₃ + CO₂ Decomposition to ammonia and carbon dioxide.

No change in Oxidation number of N, S,H and O.

H₂S can react with ZrCl₂ × 8 H₂O

ZrOCl₂ × 8 H₂O + 2 H₂S => ZrS₂ + 9 H₂O + 2 HCl

In both ZrOCl₂ × 8 H₂O and ZrS₂ zirconium has +4 oxidation number.

Exoting compounds reported bei oxidation of zirconium.

https://pubs.aip.org/aip/apl/article/10 ... -zirconium

But I don't think they can be made with Thiourea.

You would need Zr 4+ + 3 e- => Zr+
Where do the 3 electrons come from. Who is the reducer.

Suppose ammonia is the reducer
Then 2 NH₃ => N₂ + 6 H+ + 6 e-

In Summe
2 Zr 4+ + 2 NH₃ => 2 Zr+ + 6 H+ + N₂

2 (ZrOCl₂ × 8 H₂O) + (NH₂)₂CS => Zr₂S + N₂+ CO₂ + 16 H₂O + 4 HCl

[SGV]

My reducer is N-Methyl-2-Pyrollidone, I utilized NaOH to maintain the pH around 12-14.
Can you help me with this?

Thank you!

[ChenBeier]

N-Methyl-2-Pyrollidone is a organic solvent. You have inorganic compounds. Make no sense. And where does the sulfur comes from.

[SGV]

Chenbeier, please check your inbox!

[ChenBeier]

I don't answer on pn. Sorry.
I dont think NMP is able to reduce a stable oxidation number to an unstabe one. And what should be the oxidation products?

[SGV]

Sure. Thanks for the reply!