0001306830-21-000131 4 1 20210510 20210512 20210512 BLACKWELL JEAN S 0001238891 4 34 001-32410 21915321 Celanese Corp 0001306830 2820 980420726 DE 1231 222 W. LAS COLINAS BLVD., SUITE 900N IRVING TX 75039-5421 972-443-4000 222 W. LAS COLINAS BLVD., SUITE 900N IRVING TX 75039-5421 Celanese CORP 20041102 Blackstone Crystal Holdings Capital Partners (Cayman) IV Ltd. 20041022 4 1 wf-form4_162085058764886.xml FORM 4 X0306 4 2021-05-10 0 0001306830 Celanese Corp CE 0001238891 BLACKWELL JEAN S C/O CELANESE CORPORATION 222 W. LAS COLINAS BLVD., SUITE 900N IRVING TX 75039 1 0 0 0 Phantom Stock 2021-05-10 4 A 0 34.642 167.20 A Common Stock 34.642 8552.495 D Each share of phantom stock represents the right to receive one share of Common Stock or the cash value of one share of Common Stock. The reported phantom stock represents dividend equivalents on cash compensation and restricted stock units deferred under the Company's 2008 Deferred Compensation Plan (the "Plan"). As provided by the Plan, the reporting person may transfer a portion of the phantom stock account into an alternative investment account at any time. The shares of phantom stock become payable in cash or shares of Common Stock, subject to certain conditions and as provided in the Plan, on the earlier of the date previously elected by the reporting person to receive payment or upon termination of the reporting person's service as a director of the Company. /s/ Adam R. Santosuosso, Attorney-in-Fact for Jean S. Blackwell 2021-05-12