Unfortunately platinum cannot be worn by men. In recent times platinum has become an alternative to gold for men to wear. However platinum cannot be worn by men in the same way gold cannot. So as jewellery: rings etc, it cannot be worn in the same way gold cannot.
It can however, be used for the same purposes gold can, which is as a use for another purpose other than jewellery or use which is based on other than itself. An example of this is platinum buttons. Buttons are used to fasten a shirt, the purpose is not as jewellery adornment or the buttons themselves. Or likewise, a platinum watch strap, the purpose of which is to hold the actual watch face. Without buttons, the shirt cannot function, without the strap, the watch cannot be worn. Therefore in these situations the said metals can be used since they are to support the function of another item and not jewellery and use is not based on the zaat of the metal. (Where use is maqsood bi’zaat, it is HARAM to wear/use and where use is bi’tabba, it is permissible halal).
But.. To clarify once again, jewellery made from platinum (and of course gold) cannot be worn.
Now the illa for this:
There are several ahadith quoted by Allama Ibn Abideen in fatawah shami, also quoted in the text of durr Al mukhtar and mentioned in Hidaya and also Mabsut and kanz ul daqa’iq, just to mention a few, but the most pertinent ahadith state the following.
1) Narrated by Sayyedena Burayda R.A. A companion entered the majestic presence and company of Rasoolallah ﷺ and he was wearing a ring made from iron. Rasoolallah ﷺ said: why do I find the ornaments of hellfire on you? The companion immediately took of his ring and asked: Ya Rasoolallah ﷺ , what should I where a ring of? The Beloved ﷺ replied: wear a ring of silver, less than one mishkaal.
2) A companion entered the holy domain of the Beloved of Allah’s ﷺ presence wearing a ring of copper or brass. The Prophet ﷺ asked: why is it I can smell hellfire on you? Immediately the companion removed the ring.
Allama Ibn Abideen and the other akaabir fuqaha narrate that on this basis, Imam Azam, sahibayn and all akaabir fuqaha have ruled that the only material a man can wear as a ring is silver. And in fact other jewellery should not be worn. They rule that iron, copper, brass are all explicitly haram along with gold. All other metals other than silver, including platinum are implicitly haram. It is actually the amr/order of Rasoolallah ﷺ that only silver should be worn as a ring, and that too less than one mishkaal which is 4.37g!
Some modern fuqaha have done qiyaas on gold to rule platinum as haram. Whilst there is jawaz for this reasoning, above is the actual reason that fuqaha have ruled platinum as haraam.
So platinum is haram for men…
Rasoolallah ﷺ wore a ring of silver which was less than one mishkaal and was used as the famous seal of prophethood.
Allah ﷻ & His Rasool ﷺ know best.