I'm going to Macau from Baku , will fly via Beijing . Do I need visa to China?

I'm going to participate at international conference in Macau (27-31 March), I will fly via Beijing using Air Macau flights. On the way back from Macau I will fly from Macau to Moscow. I was told that I don't need visa if I'm in Beijing airport not more than 24 hours and will not leave it.Can you confirm it?
Thanks

BR,
Nariman