Pablo Herrera and Adrian Gavira won bronze.
Younousse and Tijan will take on Poland’s Michal Bryl and Grzegorz Fijalek in the last eight on Friday.
The Qatari pair lost to Americans Americans Phil Dalhausser and Nick Lucena.
The Qatari pair defeated Australians Damien Shuman and Cole Durant in the final.
The Qatari duo will take on Japan’s Yuya Ageba and Gottsu Ishijma for a place in the final.
The Qatari No.1 pair defeated Thailand’s Kitti Duangjinda and Surin Jongklang.
The seventh edition of the tournament will start at the Aspire Park on Tuesday.
The tournament will be held from November 27 to 30 2018 at Aspire park.
Team consisting of Ahmed Tijan and Cherif Younousse won 21-18 and 21-13.
Ahmed Tijan and Cherif Younousse defeated Kazakhs Alexey Sidorenko/Alexandr Dyachenko in the semifinal.
The Qataris then defeated Singapore’s Kingsley Tay ZHK and Shen Fan Yang.
Qatari pair defeated top seeds Philip Dalhausser and Nicholas Lucena in the third-place playoff
Brouwer and Meeuwsen will take on Stoyanovskiy and Velichko in the title clash on Saturday
The 20th seeds will take on fifth-seeded Dutch pairing of Alexander Brouwer and Robert Meeuwsen in the FIVB World Tour event
Qatar’s other two teams fail to progress past the first round of Katara Cup