Not directly with XenCenter but possible with XenOrchestra (Open Source)
More info: http://bit.ly/2m7FVIG
Web Self Service (retired with the launch of XenServer 6.2) was a lightweight portal which allowed individuals to operate their own virtual machines without having administrator credentials to the XenServer host. For large infrastructures, OpenStack is a full orchestration product with far greater capability; for a lightweight alternative, xvpsource.org offers a free open source product.
Related Citrix products have browser based access, for example Storefront (next generation of Web Interface)